A communication method and apparatus

Abstract

A communication method and device, the method comprising: a network device sending multicast configuration information to a terminal device, the multicast configuration information corresponding to a first multicast service, the multicast configuration information including first indication information, the first indication information indicating that the terminal device needs to send first feedback information for the first multicast service, the terminal device receiving the first multicast service according to the first multicast configuration information, and then sending the first feedback information corresponding to the first multicast service to the network device according to the first indication information in the first multicast configuration information. The method and device of the present application can implement a feedback mechanism for multicast transmission technology and improve the transmission reliability of multicast services.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a communication method and device. Background Art

[0002] In wireless communication systems, multicast transmission technology supports point-to-multipoint communication, where network devices transmit the same data to multiple terminal devices, such as mobile TV services. Currently, long-term evolution (LTE) communication systems offer two broadcast-multicast service modes: multimedia broadcast multicast service (MBMS) and single-cell point-to-multipoint (SC-PTM). When using multicast transmission technology to transmit multicast services, terminal devices must first obtain multicast configuration information and then receive the multicast service based on this information.

[0003] However, current multicast transmission technology does not support hybrid automatic repeat request (HARQ) feedback, so its reliability is relatively low. When applied to the new generation of radio access technology (NR), it cannot meet the reliability requirements of some multicast services. Summary of the Invention

[0004] The present application provides a communication method and apparatus for implementing a feedback mechanism applicable to multicast transmission and improving the transmission reliability of multicast services.

[0005] In a first aspect, an embodiment of the present application provides a communication method, which can be applied to a terminal device, or can also be applied to a chip inside the terminal device. Taking the application of this method to a terminal device as an example, in this method, the terminal device receives first multicast configuration information from a network device, the first multicast configuration information is used to indicate the sending of first feedback information for a first multicast service, wherein the first multicast configuration information corresponds to the first multicast service, the first multicast configuration information includes first indication information, the first indication information is used to indicate the sending of first feedback information for the first multicast service, and then the terminal device receives the first multicast service from the network device, and the terminal device sends the first feedback information to the network device.

[0006] By adopting this solution, on the one hand, the terminal device can provide feedback on the multicast service. On the other hand, because the first indication information indicates feedback on the first multicast service, the terminal device can provide feedback on the multicast service with higher latency requirements indicated by the network device, thereby effectively improving the reliability of the multicast service with higher latency requirements.

[0007] In one possible design, the first multicast configuration information also includes a group-radio network temporary identity (G-RNTI) associated with the first multicast service and / or an identifier of the multicast service, and the G-RNTI and / or the identifier of the multicast service are associated with the first indication information.

[0008] In this way, since the first indication information is included in the first multicast configuration information, there is no need to send the first indication information separately, which can effectively save transmission resources.

[0009] In one possible design, the first indication information indicates feedback on the first multicast service through a bit or a field.

[0010] In this way, after receiving the first indication information, the terminal device can confirm that feedback on the first multicast service is required.

[0011] In one possible design, the first indication information is used to indicate the transmission resources of the first feedback information.

[0012] In this way, on the one hand, after receiving the first indication information, the terminal device can confirm the need to provide feedback on the first multicast service. On the other hand, the network device implicitly indicates the transmission resource information of the terminal device through the downlink control information, which can effectively save transmission resources.

[0013] In one possible design, the first indication information may include a threshold value of a signal quality parameter, and the terminal device determines whether it is necessary to send feedback information based on the threshold value of the signal quality parameter. Specifically, after receiving the first indication information, the terminal device determines that the value of the signal quality parameter corresponding to the first multicast service is less than or equal to the threshold value, and only then sends the first feedback information to the network device; otherwise, the first feedback information is not sent.

[0014] In this way, the terminal device can independently decide whether to provide feedback based on the specific reception situation of the multicast service.

[0015] In one possible design, the terminal device may further receive second multicast configuration information from the network device, where the second multicast configuration information corresponds to a second multicast service. The second multicast configuration information includes second indication information, where the second indication information is used to indicate that feedback information does not need to be sent for the second multicast service. In this way, after receiving the second multicast service, the terminal device no longer provides feedback.

[0016] In this way, the terminal device can only provide feedback on services with higher latency requirements, which on the one hand improves the reliability of information transmission and on the other hand saves transmission resources.

[0017] In one possible design, when the feedback resources of the first multicast service conflict with the feedback resources of the unicast service, the terminal device can determine whether to send the first feedback information of the first multicast service to the network device based on the priority of the feedback information. Specifically, if the protocol pre-agreed that the priority of the feedback information of the multicast service is higher than the priority of the feedback information of the unicast service, the terminal device can give priority to sending the first feedback information corresponding to the first multicast service to the network device and discard the feedback information corresponding to the unicast service; if the protocol pre-agreed that the priority of the feedback information of the multicast service is not higher than the priority of the feedback information of the unicast service, the terminal device can give priority to sending the feedback information corresponding to the unicast service to the network device and discard the first feedback information corresponding to the first multicast service.

[0018] In this way, the terminal device can provide feedback on unicast services or multicast services according to the protocol to resolve resource conflicts.

[0019] In one possible design, the terminal device may further receive third indication information from the network device, where the indication information is used to indicate the priority of the feedback information of the multicast service. The third indication information may be carried in a downlink control information (DCI) or a radio resource control (RRC) message together with the multicast configuration information. In response to the third indication information, if the third indication information indicates that the priority of the feedback information of the first multicast service is the first priority (e.g., a high priority), the terminal device preferentially sends the first feedback information corresponding to the first multicast service to the network device, and discards the feedback information corresponding to the unicast service; if the third indication information indicates that the priority of the feedback information of the first multicast service is the second priority (e.g., a low priority), the terminal device preferentially sends the feedback information corresponding to the unicast service to the network device, and discards the first feedback information corresponding to the first multicast service.

[0020] In this way, the terminal device can provide feedback on the unicast service or multicast service according to the instruction of the network device to solve the problem of resource conflict.

[0021] In a possible design, the network device sends fourth indication information to the terminal device, where the fourth indication information is used to trigger the terminal device to send stop feedback confirmation information to the network device. The terminal device triggers the terminal device to send the stop feedback confirmation information to the network device due to receiving the fourth indication information. In this way, the terminal device can stop feeding back the first multicast service in a timely manner according to the indication of the network device. The terminal device releases the PUCCH resource configured for multicast feedback, thereby improving the utilization of the resource. In a possible implementation, the fourth indication information can be carried in a DCI or an RRC message or a MAC CE.

[0022] In a possible design, the stop feedback confirmation information can be in a MAC sub-protocol data unit (PDU), and the MAC sub-PDU includes a MAC sub-header and a MAC CE. The MAC sub-header includes a logical channel identifier (LCID). In a possible implementation, the stop feedback confirmation information can be indicated by the LCID. For example, when the LCID is a preset value (for example, the LCID takes a value of 33), it indicates that the terminal device stops sending feedback information for the first multicast service. In another possible implementation, the stop feedback confirmation information can be indicated by the length of the MAC CE. For example, when the length of the MAC CE is a preset length, the MAC CE with the preset length is used to indicate that the terminal device stops sending feedback information for the first multicast service. In another possible implementation, the stop feedback confirmation information can be indicated by a multicast service identifier or a G-RNTI in the MAC CE.

[0023] In a second aspect, an embodiment of the present application provides a communication method, which can be applied to a network device or a chip inside the network device. Taking the case where the method is applied to a network device as an example, in the method, the network device can send first multicast configuration information to a terminal device, where the first multicast configuration information corresponds to a first multicast service, and the first multicast configuration information includes first indication information, where the first indication information is used to indicate sending first feedback information for the first multicast service. Then, the network device sends the first multicast service to the terminal device. The network device receives the first feedback information from the terminal device.

[0024] Since the communication method described in the second aspect corresponds to the communication method described in the first aspect, the beneficial effects of the communication method described in the second aspect can be referred to the first aspect, which will not be repeated here.

[0025] In one possible design, the first multicast configuration information also includes a group-radio network temporary identifier G-RNTI associated with the first multicast service and / or an identifier of the multicast service, and the G-RNTI and / or the identifier of the multicast service are associated with the first indication information.

[0026] In one possible design, the first indication information indicates feedback on the first multicast service through a bit or a field; and / or, the first indication information is used to indicate a transmission resource of the first feedback information.

[0027] In one possible design, the network device determines the terminal device that needs to send feedback information for the first multicast service based on at least one of the service requirements of the first multicast service, the physical relative distance between the terminal device and the network device, and the channel quality of the terminal device.

[0028] In one possible design, the network device sends second multicast configuration information to the terminal device, where the second multicast configuration information corresponds to a second multicast service, and the second multicast configuration information includes second indication information, which is used to indicate that the terminal device does not need to send feedback information for the second multicast service.

[0029] In one possible design, before the network device receives the first feedback information from the terminal device, the network device sends third indication information to the terminal device, where the third indication information is used to indicate the priority of the feedback information of the first multicast service. The third indication information is carried in downlink control information DCI, and the DCI is used to schedule a physical downlink shared channel PDSCH that carries the first multicast service.

[0030] In one possible design, the network device sends fourth indication information to the terminal device, where the fourth indication information is used to instruct the terminal device to stop sending feedback information for the first multicast service;

[0031] Receive stop feedback confirmation information from the terminal device, where the stop feedback confirmation information is used to instruct the terminal device to stop sending feedback information for the first multicast service.

[0032] In one possible design, the stop feedback confirmation information is indicated by a logical channel identifier LCID, and the LCID is carried by a media access control MAC subheader; or, the stop feedback confirmation information is indicated by the fifth indication information in the MAC control unit CE; or, the stop feedback confirmation information is indicated by the length of the MAC CE.

[0033] In one possible design, a network device receives feedback capability information from a terminal device, where the feedback capability information is used to indicate the ability of the terminal device to send unicast feedback information and multicast feedback information on the same feedback resource; the unicast feedback information is feedback information corresponding to a unicast service, and the multicast feedback information is feedback information corresponding to a multicast service.

[0034] In a third aspect, embodiments of the present application provide a first communication device configured to perform the method of the first aspect or any possible embodiment described above. Specifically, the first communication device may include modules configured to perform the method of the first aspect or any possible embodiment, such as a processing module and a transceiver module. Exemplarily, the transceiver module may include a transmitting module and a receiving module. The transmitting module and the receiving module may be different functional modules, or they may be the same functional module but capable of performing different functions. Exemplarily, the first communication device is a terminal device, or a chip or other component provided in a terminal device. Exemplarily, the communication device is a terminal device. Below, the first communication device is taken as an example of a terminal device. For example, the transceiver module may be implemented by a transceiver, and the processing module may be implemented by a processor. Alternatively, the transmitting module may be implemented by a transmitter, and the receiving module may be implemented by a receiver. The transmitter and receiver may be different functional modules, or they may be the same functional module but capable of performing different functions. If the first communication device is a terminal device, the transceiver may be implemented, for example, by an antenna, feeder, codec, etc. in the terminal device. Alternatively, if the first communication device is a chip provided in a terminal device, then the transceiver (or, transmitter and receiver) is, for example, a communication interface in the chip, which is connected to a radio frequency transceiver component in the terminal device to enable information transmission and reception through the radio frequency transceiver component. In the introduction of the third aspect, the first communication device is still described as a terminal device, and the processing module and the transceiver module are used as examples. Among them:

[0035] The transceiver module is used to receive first multicast configuration information from a network device, where the first multicast configuration information is used to indicate sending first feedback information for a first multicast service, wherein the first multicast configuration information corresponds to the first multicast service, and the first multicast configuration information includes first indication information, and the first indication information is used to indicate sending first feedback information for the first multicast service.

[0036] The processing module is configured to determine, based on the first indication information, that feedback on the first multicast service is required.

[0037] The transceiver module is further configured to receive a first multicast service from a network device, and the terminal device sends first feedback information to the network device.

[0038] In one possible design, the first multicast configuration information also includes a group-radio network temporary identity (G-RNTI) associated with the first multicast service and / or an identifier of the multicast service, and the G-RNTI and / or the identifier of the multicast service are associated with the first indication information.

[0039] In one possible design, the first indication information indicates feedback on the first multicast service through a bit or a field.

[0040] In one possible design, the first indication information is used to indicate the transmission resources of the first feedback information.

[0041] In one possible design, the first indication information may include a threshold value of a signal quality parameter, and the receiving module determines whether it is necessary to send feedback information based on the threshold value of the signal quality parameter. Specifically, after the receiving module receives the first indication information, the processing module determines that the value of the signal quality parameter corresponding to the first multicast service is less than or equal to the threshold value, and then sends the first feedback information to the network device through the transceiver module; otherwise, the first feedback information is not sent.

[0042] In one possible design, the transceiver module is further configured to receive second multicast configuration information from the network device, the second multicast configuration information corresponding to a second multicast service; the second multicast configuration information includes second indication information, the second indication information being configured to indicate that feedback information does not need to be sent for the second multicast service. In this way, after receiving the second multicast service, the terminal device no longer provides feedback.

[0043] In one possible design, when feedback resources for a first multicast service conflict with feedback resources for a unicast service, the processing module may determine whether to send first feedback information for the first multicast service to the network device based on the priority of the feedback information. Specifically, if the protocol pre-determines that the priority of feedback information for a multicast service is higher than the priority of feedback information for a unicast service, the transceiver module may prioritize sending the first feedback information corresponding to the first multicast service to the network device and discard the feedback information corresponding to the unicast service; if the protocol pre-determines that the priority of feedback information for a multicast service is not higher than the priority of feedback information for a unicast service, the transceiver module may prioritize sending the feedback information corresponding to the unicast service to the network device and discard the first feedback information corresponding to the first multicast service.

[0044] In one possible design, the transceiver module may further receive third indication information from the network device, where the indication information is used to indicate the priority of the feedback information of the multicast service. The third indication information may be carried in a downlink control information (DCI) or a radio resource control (RRC) message together with the multicast configuration information. In response to the third indication information, if the third indication information indicates that the priority of the feedback information of the first multicast service is the first priority (e.g., a high priority), the processing module determines to preferentially send the first feedback information corresponding to the first multicast service to the network device through the transceiver module, and discard the feedback information corresponding to the unicast service; if the third indication information indicates that the priority of the feedback information of the first multicast service is the second priority (e.g., a low priority), the processing module determines to preferentially send the feedback information corresponding to the unicast service to the network device through the transceiver module, and discard the first feedback information corresponding to the first multicast service.

[0045] In one possible design, the transceiver module is further used to send a fourth indication message to the terminal device, and the fourth indication message is used to trigger the terminal device to send a stop feedback confirmation message to the network device. Since the terminal device receives the fourth indication message, it triggers the terminal device to send a stop feedback confirmation message to the network device. The fourth indication message can be carried in a DCI or RRC message or a media access control (MAC) control element (CE). In this way, the terminal device can stop providing feedback on the first multicast service in a timely manner according to the instruction of the network device. The terminal device will release the PUCCH resources configured for multicast feedback to improve resource utilization.

[0046] In one possible design, the stop feedback confirmation information may be a MAC sub-protocol data unit (PDU). The MAC sub-PDU includes a MAC sub-header and a MAC CE, and the MAC sub-header includes a logical channel identifier (LCID). One possible way is that the stop feedback confirmation information may be indicated by the logical channel identifier LCID. Exemplarily, if the LCID is a preset value (for example, a value of 33), it indicates that the terminal device stops sending feedback information for the first multicast service. Another possible way is that the stop feedback confirmation information may be indicated by the length of the MAC CE. Exemplarily, if the length of the MAC CE is a preset length, the MAC CE with the preset length is used to indicate the stop of sending feedback information for the first multicast service. Other possible ways are that the stop feedback confirmation information may be indicated by the multicast service identifier or G-RNTI in the MAC CE.

[0047] Regarding the technical effects brought about by the third aspect or various optional implementations, reference may be made to the introduction to the technical effects of the first aspect or corresponding implementations.

[0048] In a fourth aspect, a second communication device is provided. The second communication device is used to execute the method of the second aspect or any possible implementation method. Specifically, the second communication device may include modules for executing the method of the second aspect or any possible implementation method, such as a processing module and a transceiver module. Exemplarily, the transceiver module may include a transmitting module and a receiving module. The transmitting module and the receiving module may be different functional modules, or may be the same functional module but capable of implementing different functions. Exemplarily, the communication device is a network device. The following takes the second communication device as an example of a network device. For example, the transceiver module may be implemented by a transceiver, and the processing module may be implemented by a processor. Alternatively, the transmitting module may be implemented by a transmitter, and the receiving module may be implemented by a receiver. The transmitter and the receiver may be different functional modules, or may be the same functional module but capable of implementing different functions. If the second communication device is a network device, the transceiver is implemented, for example, by an antenna, feeder, codec, etc. in the network device. Alternatively, if the second communication device is a chip provided in a network device, then the transceiver (or, transmitter and receiver) is, for example, a communication interface in the chip, which is connected to a radio frequency transceiver component in the network device to transmit and receive information through the radio frequency transceiver component. In the introduction of the fourth aspect, the second communication device is still described as a network device, and the processing module and the transceiver module are used as examples. Among them:

[0049] The processing module is configured to determine first multicast configuration information.

[0050] A transceiver module is used to send first multicast configuration information to a terminal device, where the first multicast configuration information corresponds to a first multicast service, and the first multicast configuration information includes first indication information, where the first indication information is used to indicate sending first feedback information for the first multicast service; thereafter, the transceiver module sends the first multicast service to the terminal device, and receives the first feedback information from the terminal device.

[0051] In one possible design, the first multicast configuration information also includes a group-radio network temporary identifier G-RNTI associated with the first multicast service and / or an identifier of the multicast service, and the G-RNTI and / or the identifier of the multicast service are associated with the first indication information.

[0052] In one possible design, the first indication information indicates feedback on the first multicast service through a bit or a field; and / or, the first indication information is used to indicate a transmission resource of the first feedback information.

[0053] In one possible design, the processing module is used to determine the terminal device that needs to send feedback information for the first multicast service based on at least one of the service requirements of the first multicast service, the physical relative distance between the terminal device and the network device, and the channel quality of the terminal device.

[0054] In one possible design, the transceiver module is also used to send second multicast configuration information to the terminal device, where the second multicast configuration information corresponds to a second multicast service, and the second multicast configuration information includes second indication information, which is used to indicate that the terminal device does not need to send feedback information for the second multicast service.

[0055] In one possible design, the transceiver module is further configured to, before receiving the first feedback information from the terminal device, cause the network device to send third indication information to the terminal device, where the third indication information is used to indicate the priority of the feedback information of the first multicast service. The third indication information is carried in downlink control information DCI, and the DCI is used to schedule a physical downlink shared channel PDSCH that carries the first multicast service.

[0056] In one possible design, the transceiver module is also used to send a fourth indication message to the terminal device, wherein the fourth indication message is used to instruct the terminal device to stop sending feedback information for the first multicast service; and is also used to receive a stop feedback confirmation message from the terminal device, wherein the stop feedback confirmation message is used to instruct the terminal device to stop sending feedback information for the first multicast service.

[0057] In one possible design, the stop feedback confirmation information is indicated by a logical channel identifier LCID, and the LCID is carried by a media access control MAC subheader; or, the stop feedback confirmation information is indicated by the fifth indication information in the MAC control unit CE; or, the stop feedback confirmation information is indicated by the length of the MAC CE.

[0058] In one possible design, the transceiver module is also used to receive feedback capability information from the terminal device, and the feedback capability information is used to indicate the ability of the terminal device to send unicast feedback information and multicast feedback information on the same feedback resource; the unicast feedback information is feedback information corresponding to the unicast service, and the multicast feedback information is feedback information corresponding to the multicast service.

[0059] In a fifth aspect, the present application provides a communication device, which may be a terminal device or a chip provided inside a terminal device. The communication device has the function of implementing the above-mentioned first aspect. For example, the communication device includes a processor, and the communication device may also include a transceiver, the transceiver is used to send and receive signals, and the processor executes program instructions to complete the method in any possible design or implementation of the above-mentioned first aspect. Among them, the communication device may also include one or more memories, and the memory is used to couple with the processor. The one or more memories may be integrated with the processor or may be provided separately from the processor, which is not limited by the present application. The memory may store the necessary computer programs or instructions for implementing the functions involved in the above-mentioned first aspect. The processor may execute the computer program or instructions stored in the memory. When the computer program or instructions are executed, the communication device implements the method in any possible design or implementation of the above-mentioned first aspect.

[0060] In one possible design, the communication device includes a processor and a memory, and the memory may store the necessary computer programs or instructions for implementing the functions of the first aspect. The processor may execute the computer program or instructions stored in the memory. When the computer program or instructions are executed, the communication device implements the method of any possible design or implementation of the first aspect.

[0061] In one possible design, the communication device includes at least one processor and an interface circuit, wherein the at least one processor is used to communicate with other devices through the interface circuit and execute the method performed by the terminal device in any possible design or implementation of the first aspect above.

[0062] In a sixth aspect, the present application provides a communication device, which may be a network device or a chip arranged inside a network device. The communication device is capable of implementing the functions involved in the second aspect above. For example, the communication device includes a processor, and the communication device may also include a transceiver, the transceiver is used to send and receive signals, and the processor executes program instructions to complete the method in any possible design or implementation of the second aspect above. The communication device may also include one or more memories, which are used to couple with the processor. The one or more memories may be integrated with the processor or may be provided separately from the processor, which is not limited by the present application. The memory may store the necessary computer programs or instructions for implementing the functions involved in the second aspect above. The processor may execute the computer program or instructions stored in the memory. When the computer program or instructions are executed, the communication device implements the method in any possible design or implementation of the second aspect above.

[0063] In one possible design, the communication device includes a processor and a memory, and the memory may store the necessary computer programs or instructions for implementing the functions involved in the second aspect. The processor may execute the computer program or instructions stored in the memory. When the computer program or instructions are executed, the communication device implements the method in any possible design or implementation of the second aspect.

[0064] In one possible design, the communication device includes at least one processor and an interface circuit, wherein the at least one processor is used to communicate with other devices through the interface circuit and execute the method in any possible design or implementation of the above-mentioned second aspect.

[0065] In the seventh aspect, the present application provides a computer-readable storage medium, which stores computer-readable instructions. When a computer reads and executes the computer-readable instructions, the computer executes the method in any possible design of the first aspect or the second aspect above.

[0066] In an eighth aspect, the present application provides a computer program product, which, when read and executed by a computer, enables the computer to execute the method in any possible design of the first aspect or the second aspect above.

[0067] In a ninth aspect, the present application provides a chip comprising a processor, wherein the processor is coupled to a memory and is configured to read and execute a software program stored in the memory to implement a method in any possible design of the first or second aspect above.

[0068] In a tenth aspect, the present application provides a communication system, comprising a terminal device and a network device, wherein the terminal device is used to implement the method in any possible design of the above-mentioned first aspect, and the network device is used to implement the method in any possible design of the above-mentioned first aspect.

[0069] These and other aspects of the present application will become more readily apparent from the description of the following embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] Figure 1 A schematic diagram of a network architecture applicable to an embodiment of the present application;

[0071] Figure 2 This is another network architecture diagram applicable to the embodiments of the present application;

[0072] Figure 3 This is another network architecture diagram applicable to the embodiments of the present application;

[0073] Figure 4A Schematic diagram of multicast service transmission for network devices;

[0074] Figure 4B Schematic diagram of obtaining multicast configuration information for terminal devices;

[0075] Figure 5 A schematic diagram of an interaction method for a communication method provided in an embodiment of the present application;

[0076] Figure 6A and Figure 6B A schematic diagram of a MAC CE structure provided in an embodiment of the present application;

[0077] Figures 7 to 10 A schematic diagram of another communication method interaction provided in an embodiment of the present application;

[0078] 11A to 11D Schematic diagram of the frame structure in the embodiment of the present application;

[0079] Figures 12A to 12G Schematic diagrams of other frame structures and mapping patterns provided in embodiments of the present application;

[0080] Figure 13 A possible exemplary block diagram of the apparatus involved in the embodiments of the present application;

[0081] Figure 14 A schematic diagram of the structure of a terminal device provided in an embodiment of the present application;

[0082] Figure 15 A schematic diagram of the structure of a network device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0083] The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application.

[0084] First, some terms in the embodiments of the present application are explained to facilitate understanding by those skilled in the art.

[0085] (1) Terminal device: It can be a wireless terminal device that can receive network device scheduling and instruction information. The wireless terminal device can be a device that provides voice and / or data connectivity to users, or a handheld device with wireless connection function, or other processing equipment connected to a wireless modem. The terminal device can communicate with one or more core networks or the Internet via a radio access network (RAN). The terminal device can be a mobile terminal device, such as a mobile phone (or "cellular" phone, mobile phone), a computer and a data card. For example, it can be a portable, pocket-sized, handheld, computer-built-in or vehicle-mounted mobile device that exchanges voice and / or data with the radio access network. For example, personal communication service (PCS) phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistants (PDAs), tablet computers (Pads), computers with wireless transceiver functions, and other devices. A wireless terminal device may also be referred to as a system, a subscriber unit, a subscriber station, a mobile station, a mobile station (MS), a remote station (remotestation), an access point (AP), a remote terminal, an access terminal, a user terminal, a user agent, a subscriber station (SS), a customer premises equipment (CPE), a terminal, a user equipment (UE), a mobile terminal (MT), etc. A terminal device may also be a wearable device or a next-generation communication system, for example, a terminal device in a 5G communication system or a terminal device in a future-evolved public land mobile network (PLMN).

[0086] (2) Network equipment: It can be a device in a wireless network, for example, a network device can be a radio access network (RAN) node (or device) that connects a terminal device to a wireless network, which can also be called a base station. Currently, some examples of RAN equipment are: a new generation Node B (gNodeB) in a 5G communication system, a transmission reception point (TRP), an evolved Node B (eNB), a radio network controller (RNC), a Node B (NB), a base station controller (BSC), a base transceiver station (BTS), a home base station (e.g., home evolved NodeB, or home Node B, HNB), a base band unit (BBU), or a wireless fidelity (Wi-Fi) access point (AP). In addition, in a network structure, a network device can include a centralized unit (CU) node, a distributed unit (DU) node, or a RAN device including a CU node and a DU node. In addition, in other possible cases, the network device may be another device that provides wireless communication functions for the terminal device. The embodiments of this application do not limit the specific technology and specific device form used by the network device. For ease of description, in the embodiments of this application, the device that provides wireless communication functions for the terminal device is referred to as the network device.

[0087] (3) Radio resource control (RRC) state. A terminal device has three RRC states: RRC connected state, RRC idle state, and inactive state.

[0088] RRC connected state (or, can also be simply referred to as connected state. In this article, "connected state" and "RRC connected state" are the same concept and the two names can be interchanged): the terminal device establishes an RRC connection with the network and can transmit data.

[0089] RRC idle state (or, can also be simply referred to as idle state. In this article, "idle state" and "RRC idle state" are the same concept and the two names can be interchanged): the terminal device has not established an RRC connection with the network, and the base station has not stored the context of the terminal device. If the terminal device needs to enter the RRC connected state from the RRC idle state, it needs to initiate the RRC connection establishment process.

[0090] RRC inactive state (or, can also be referred to as inactive state for short. In this article, "deactivated state", "deactivated state", "inactive state", "RRC inactive state" and "RRC deactivated state" are the same concept, and these names can be interchanged): the terminal device previously entered the RRC connected state, and then the base station released the RRC connection, but the base station saved the context of the terminal device. If the terminal device needs to enter the RRC connected state again from the RRC inactive state, it is necessary to initiate an RRC connection recovery process (or called an RRC connection re-establishment process). Compared with the RRC establishment process, the RRC recovery process has a shorter delay and smaller signaling overhead. However, the base station needs to save the context of the terminal device, which will occupy the storage overhead of the base station.

[0091] (4) The terms "system" and "network" in the embodiments of the present application can be used interchangeably. "At least one" means one or more, and "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, "at least one of A, B and C" includes A, B, C, AB, AC, BC or ABC.

[0092] Furthermore, unless otherwise specified, ordinal numbers such as "first" and "second" in the embodiments of this application are used to distinguish between multiple objects and are not used to define the order, timing, priority, or importance of multiple objects. For example, the first threshold and the second threshold are only used to distinguish different thresholds and do not indicate a difference in priority or importance between the two thresholds.

[0093] The technical solution of this application is further described in detail below in conjunction with the accompanying drawings.

[0094] Figure 1 This is a schematic diagram of a network architecture applicable to the embodiment of this application. Figure 1As shown, the terminal device 130 can access the wireless network to obtain services of the external network (such as the Internet) through the wireless network, or communicate with other devices through the wireless network, such as communicating with other terminal devices. The wireless network includes a radio access network (RAN) device 110 and a core network (CN) device 120, wherein the RAN device 110 is used to access the terminal device 130 to the wireless network, and the CN device 120 is used to manage the terminal device and provide a gateway for communicating with the external network. It should be understood that Figure 1 The number of devices in the communication system shown is for illustration only, and the embodiments of the present application are not limited thereto. In actual applications, the communication system may further include more terminal devices 130 , more RAN devices 110 , and other devices.

[0095] A CN may include multiple CN devices 120. Figure 1 When the network architecture shown is applicable to a 5G communication system, the CN device 120 may be an access and mobility management function (AMF) entity, a session management function (SMF) entity, or a user plane function (UPF) entity. Figure 1 When the network architecture shown is applicable to an LTE communication system, the CN device 120 may be a mobility management entity (MME) and a serving gateway (S-GW).

[0096] Figure 2 This is another network architecture diagram applicable to the embodiment of this application. Figure 2 As shown, the network architecture includes CN equipment, RAN equipment, and terminal equipment. The RAN equipment includes a baseband device and a radio frequency device, wherein the baseband device can be implemented by one node or multiple nodes, and the radio frequency device can be implemented independently from the baseband device, or integrated into the baseband device, or some functions can be integrated independently and some functions can be integrated into the baseband device. For example, in an LTE communication system, the RAN equipment (eNB) includes a baseband device and a radio frequency device, wherein the radio frequency device can be arranged remotely from the baseband device, for example, a remote radio unit (RRU) is a remote radio unit arranged relative to the BBU.

[0097] The communication between RAN equipment and terminal equipment follows a certain protocol layer structure. For example, the control plane protocol layer structure may include the functions of the radio resource control (RRC) layer, packet data convergence protocol (PDCP) layer, radio link control (RLC) layer, media access control (MAC) layer, and physical layer. The user plane protocol layer structure may include the functions of the PDCP layer, RLC layer, MAC layer, and physical layer. In one possible implementation, the service data adaptation protocol (SDAP) layer may also be included above the PDCP layer.

[0098] RAN equipment can implement the functions of protocol layers such as RRC, PDCP, RLC and MAC by one node, or can implement the functions of these protocol layers by multiple nodes. For example, in an evolutionary structure, RAN equipment can include a centralized unit (CU) and a distributed unit (DU), and multiple DUs can be centrally controlled by one CU. Figure 2 As shown, CU and DU can be divided according to the protocol layers of the wireless network, for example, the functions of the PDCP layer and above protocol layers are set in CU, and the functions of the protocol layers below PDCP, such as the RLC layer and MAC layer, are set in DU.

[0099] This protocol layer division is merely an example. Division can also be performed at other protocol layers, such as the RLC layer, where functions at and above the RLC layer are located in the CU, while functions at layers below the RLC layer are located in the DU. Alternatively, division can be performed within a specific protocol layer, such as where some functions at the RLC layer and functions at layers above the RLC layer are located in the CU, while the remaining functions at the RLC layer and functions at layers below the RLC layer are located in the DU. Furthermore, division can be performed in other ways, such as by latency, where functions that require processing time to meet latency requirements are located in the DU, while functions that do not require latency requirements are located in the CU.

[0100] In addition, the radio frequency device can be independently integrated and not placed in the DU, or it can be integrated in the DU, or part of it can be remotely located and part of it can be integrated in the DU. There is no limitation here.

[0101] Figure 3 This is another network architecture diagram applicable to the embodiment of this application. Figure 2 The network architecture shown, Figure 3The control plane (CP) and user plane (UP) of the CU can also be separated and implemented into different entities, namely the control plane (CP) CU entity (i.e., CU-CP entity) and the user plane (UP) CU entity (i.e., CU-UP entity).

[0102] In the above network architecture, the signaling generated by the CU can be sent to the terminal device through the DU, or the signaling generated by the terminal device can be sent to the CU through the DU. The DU can directly encapsulate the signaling through the protocol layer and transparently transmit it to the terminal device or CU without parsing it. In the following embodiments, if the transmission of such signaling between the DU and the terminal device is involved, then the sending or receiving of the signaling by the DU includes this scenario. For example, the signaling of the RRC or PDCP layer will eventually be processed as the signaling of the PHY layer and sent to the terminal device, or converted from the received signaling of the PHY layer. Under this architecture, the signaling of the RRC or PDCP layer can also be considered to be sent by the DU, or sent by the DU and the RF loader.

[0103] above Figure 1 、 Figure 2 or Figure 3 The network architecture shown can be applicable to communication systems of various radio access technologies (RATs), for example, an LTE communication system, a 5G (or new radio, NR) communication system, or a transition system between an LTE communication system and a 5G communication system, which can also be called a 4.5G communication system, and of course, a future communication system. The network architecture and service scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided in the embodiments of the present application. It is known to those skilled in the art that with the evolution of the communication network architecture and the emergence of new service scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0104] The apparatus in the following embodiments of the present application may be located in a terminal device or a network device, depending on the functions implemented. When the above CU-DU structure is adopted, the network device may be a CU node, a DU node, or a RAN device including a CU node and a DU node.

[0105] exist Figure 1 、 Figure 2 or Figure 3In the network architecture shown, network devices can transmit service data to terminal devices in a multicast manner, such as through SC-PTM technology to achieve multicast transmission. In the SC-PTM broadcast mode, the access network device configures the single-cell multicast control logical channel (SC-MCCH) through the SIB, which includes the time domain location of the SC-MCCH. The SC-PTM configuration information carried by the SC-MCCH includes the configuration information of the single-cell multicast traffic logical channel (SC-MTCH), which includes the temporary mobile group identity (TMGI), the session identifier (session ID), the G-RNTI for scrambling the DCI, and the configuration information of time domain discontinuous reception (DRX). It should be noted that the two logical channels SC-MCCH and SC-MTCH are both mapped to the physical downlink shared channel (PDSCH) at the physical layer, and the DCI is carried on the physical downlink control channel (PDCCH). In SC-PTM technology, the physical downlink share channel (PDSCH) can be used to transmit multicast services. The network device can send downlink control information (DCI) carried on the physical downlink control channel (PDCCH) to a group of terminal devices in a cell. The DCI is used to schedule the multicast PDSCH that carries the multicast service. The DCI can be scrambled by the group-radio network temporary identity (G-RNTI) associated with the multicast service. The terminal device obtains the physical downlink channel PDSCH scheduled by detecting the DCI scrambled by the group radio network temporary identifier (G-RNTI) G-RNTI, and then obtains the service data carried by the PDSCH.

[0106] See also Figure 4AAs shown, a scenario in which a network device transmits three types of multicast services is illustrated. The network device may allocate G-RNTI 1 for the first multicast service, G-RNTI 2 for the second multicast service, and G-RNTI 3 for the third multicast service, that is, the G-RNTI associated with the first multicast service is G-RNTI 1, the G-RNTI associated with the second multicast service is G-RNTI 2, and the G-RNTI associated with the third multicast service is G-RNTI 3. In order to receive the first multicast service and the second multicast service, a first group of terminal devices (for example, including terminal device 1, terminal device 2, and terminal device 3) needs to obtain first multicast configuration information of the first multicast service, which is used to instruct the first group of terminal devices to receive the first multicast service (for example, the first multicast configuration information may include G-RNTI 1 associated with the first multicast service), and receive DCI1 for scheduling multicast PDSCH1 (multicast PDSCH1 is used to carry the first multicast service) from the network device according to G-RNTI 1, and then receive multicast PDSCH1. Similarly, in order to receive the second multicast service, the first group of terminal devices (for example, terminal device 1, terminal device 2 and terminal device 3) needs to obtain the second multicast configuration information of the second multicast service (for example, the second multicast configuration information may include G-RNTI 2 associated with the second multicast service). The second multicast configuration information is used to instruct the first group of terminal devices to receive the second multicast service, and receive DCI2 from the network device for scheduling multicast PDSCH2 (multicast PDSCH2 is used to carry the second multicast service) according to G-RNTI 2, and then receive multicast PDSCH2.

[0107] Similarly, in order to receive the second multicast service, the second group of terminal devices (for example, including terminal device 4, terminal device 5 and terminal device 6) needs to obtain the second multicast configuration information of the second multicast service (for example, the second multicast configuration information may include G-RNTI 2 associated with the second multicast service). The second multicast configuration information is used to instruct the second group of terminal devices to receive multicast service 2, and receive DCI2 from the network device for scheduling multicast PDSCH2 (multicast PDSCH2 is used to carry the second multicast service) according to G-RNTI 2, and then receive multicast PDSCH2.

[0108] For example, Figure 4B This is a deployment diagram of a mobile communication network, including one or more base stations. Each base station manages one or more cells. Figure 4BIn the example, a base station manages a cell. In each cell, there are several UEs, which can be connected to the base station through the air interface and enjoy communication services after accessing the cell. Taking sports live broadcast as an example, if multiple user devices request sports live broadcast services at the same time, the base station can use a single point-to-multipoint multicast bearer PDSCH1 to send data to multiple terminal devices (such as Figure 4B UE 1, UE 2, UE 3) in the example transmit the same video content.

[0109] It can be seen that multicast transmission technology can effectively guarantee the user's service experience, and the more terminal devices there are, the higher the utilization rate of network resources. However, the current multicast transmission technology does not support hybrid automatic repeat request (HARQ) feedback, so the terminal device does not provide feedback on whether the multicast service is correctly received after receiving the multicast service. For some multicast services with relatively high reliability requirements, the current multicast transmission technology cannot meet the reliability requirements of some multicast services. Based on this, the embodiment of the present application improves the current multicast transmission technology so that the current multicast transmission technology supports a feedback mechanism, and then the terminal device can provide feedback on the multicast service that requires feedback based on the indication information of the network device, thereby improving the reliability of the multicast service.

[0110] The following describes in detail how the terminal device provides feedback on the multicast service with reference to the accompanying drawings.

[0111] Example 1

[0112] Figure 5 A flow chart of a communication method provided in an embodiment of the present application may include the following steps.

[0113] Step 501: A network device sends first multicast configuration information to a terminal device. The first multicast configuration information corresponds to a first multicast service. The first multicast configuration information includes first indication information. The first indication information is used to indicate sending first feedback information for the first multicast service.

[0114] It should be noted that the first multicast configuration information is used to instruct the terminal device to receive the first multicast service. Optionally, the first multicast configuration information can be carried in an RRC message or a system message or a common channel. The first multicast configuration information is multicast configuration information corresponding to the first multicast service, and is used to instruct the terminal device to receive the first multicast service according to the first multicast configuration information, wherein the first multicast configuration information includes the first indication information. Generally, the multicast configuration information may also include at least one of the following parameters: (1) G-RNTI, (2) identifier of the multicast service, (3) BWP information corresponding to the G-RNTI, (4) PDSCH scrambling sequence of the multicast service, (5) DRX parameter of the G-RNTI, (6) demodulation reference signal, (7) rate matching reference signal, (8) radio bearer identifier and (9) security configuration identifier. Among them:

[0115] (1) The G-RNTI corresponds to the multicast service in a one-to-one manner. In this embodiment of the present application, the first multicast configuration information may further include a G-RNTI 1 that corresponds to the first multicast service in a one-to-one manner. In other words, the G-RNTI 1 is equivalent to the identifier of the first multicast service. In this embodiment of the present application, the first indication information may be associated with the G-RNTI 1, that is, the first indication information corresponds to the first multicast service.

[0116] (2) The identifier of the multicast service includes the Internet Protocol (IP) address and / or port number of the multicast service.

[0117] Among them, the multicast service identifier can be sent by the application server to the core network device, and the core network device then sends the multicast service identifier to the network device, or the multicast service identifier can also be a temporary mobile group identity (TMGI). In an embodiment of the present application, the first multicast configuration information can also include the IP address and / or port number of the first multicast service, and the first indication information can be associated with the IP address and / or port number of the first multicast service. Specifically, the first indication information can instruct the terminal device to send first feedback information for the multicast service corresponding to the first IP address and / or first port number.

[0118] (3) The BWP information corresponding to the G-RNTI includes at least one of the following: bandwidth, frequency position, subcarrier spacing (SCS), cyclic prefix (CP) length, control resource set (CORESET) related configuration information, and PDSCH related configuration information. The COREST information is used to indicate the time-frequency resources where the G-RNTI PDCCH is located. In this embodiment of the present application, the first multicast configuration information may also include the BWP information corresponding to G-RNTI1.

[0119] (4) PDSCH scrambling sequence for multicast services: The terminal device applies this PDSCH scrambling sequence to descramble the PDSCH of the multicast service.

[0120] (5) DRX parameter of G-RNTI: The terminal device uses this DRX parameter to perform G-RNTI detection.

[0121] (6) Demodulation Reference Signal: The terminal device uses this demodulation reference signal to demodulate the PDSCH scheduled by the G-RNTI.

[0122] (7) Rate matching reference signal: When receiving the PDSCH scheduled by the G-RNTI, the terminal device excludes the position corresponding to the rate matching reference signal.

[0123] (8) The radio bearer identifier is used to identify the radio bearer corresponding to the first multicast service. The radio bearer can be a data radio bearer, such as a DRB (Data Radio Bearer), or a multicast radio bearer introduced for the multicast service, such as an MRB (Multicast Radio Bearer).

[0124] (9) The security configuration identifier is used to identify the security configuration corresponding to the first multicast service. The security configuration may include at least one of an encryption algorithm indication and an integrity protection algorithm indication.

[0125] In a possible embodiment, in step 501, the network device may indicate to the terminal device whether it needs to send feedback information by using the first indication information in an explicit indication or implicit indication method.

[0126] Specifically, the network device may send the first indication information for indicating whether to provide feedback on the first multicast service to the terminal device in any one or more of the following ways.

[0127] Method 1

[0128] The first indication information indicates whether the terminal device should provide feedback on the received first multicast service. For example, the network device may indicate the network device 1 to provide feedback on the first multicast service through a bit or a special field in the first indication information.

[0129] It should be noted that the network device may also use two or more bits in the first indication information to provide feedback on the first multicast service. In other words, the network device may also use two or more fields in the first indication information to indicate feedback on the first multicast service. This embodiment of the present application does not specifically limit this.

[0130] Method 2

[0131] The first indication information implicitly indicates whether the terminal device provides feedback on the received first multicast service. For example, network device 1 may indicate in the first indication information the transmission resource of the first feedback information corresponding to the first multicast service, and the transmission resource is used to carry the first feedback information of the terminal device on the first multicast service.

[0132] For example, the network device configures the PUCCH resource used for hybrid automatic repeat request (HARQ) feedback of the first multicast service for the terminal device, which is equivalent to instructing the terminal device to provide feedback. The PUCCH resource may be different from the PUCCH resource used for HARQ feedback of the unicast service.

[0133] Method 3

[0134] The first indication information includes auxiliary parameters, and the terminal device determines whether to provide feedback for the first multicast service through the auxiliary parameters. For example, the network device can transmit the threshold value of the signal quality parameter through the first indication information. The signal quality parameter can be at least one of the following: reference signal receiving power (reference signal receiving power, RSRP), reference signal receiving quality (reference signal receiving quality, RSRQ) and received signal strength indication (received signal strength indication, RSSI), channel quality information (channel quality information, CQI), etc. After the terminal device receives the first indication information, the terminal device will further confirm whether to provide feedback based on the threshold value and the value of the measured signal quality parameter. For details, please refer to the following step 504.

[0135] Method 4

[0136] The network device can indicate whether the terminal device feeds back the first multicast service in the first indication information in combination with at least two of the above-described manner one to the above-described manner three.

[0137] For example, the network device can indicate the terminal device in combination with the manner one and the manner three. For example, the network device indicates that the terminal device needs to feed back the first multicast service by using one bit or one field in the first indication information, and indicates the transmission resource of the first feedback information corresponding to the first multicast service in the first indication information. Correspondingly, the terminal device determines that the terminal device needs to feed back the first multicast service according to the bit or the field in the first indication information, and sends the first feedback information to the network device through the transmission resource indicated in the first indication information.

[0138] In a possible embodiment, before step 501 is performed, the network device needs to determine the terminal device that needs to feed back the multicast service. The determination method of the network device can include one or more of the following manners.

[0139] Manner one

[0140] The network device can determine the terminal device that needs to feed back the multicast service according to the service requirement of the multicast service corresponding to the group terminal device to which the terminal device belongs. For example, whether the multicast service sent by the network device to the terminal device is the multicast service interested by the terminal device. If yes, it is determined that the terminal device needs to feed back the multicast service. The group terminal device is a collection of terminal devices receiving the same multicast service, for example, Figure 4A In the above embodiment, the terminal device 1, the terminal device 2 and the terminal device 3 constitute the first group terminal device receiving the multicast service 1.

[0141] For example, the group terminal device to which the terminal device in the above embodiment belongs is the first group terminal device in the above embodiment, and it is assumed that the service requirement of the first multicast service corresponding to the first group terminal device has a high reliability requirement. Figure 4A

[0142] A possible manner is that the network device determines that part of the terminal devices in the first group terminal device receiving the first multicast service need to feed back the first multicast service. The network device can configure part of the terminal devices of the first group terminal device to feed back the first multicast service, and part of the terminal devices do not feed back the first multicast service. In principle, since the service requirement of the first multicast service has a high reliability requirement, the terminal devices receiving the first multicast service should all be configured to feed back. However, considering at least one of the feedback resource that can be provided by the network, the channel quality between the terminal device and the network device, and the receiving capability of the terminal device, the network device selects part of the terminal devices to configure the feedback resource, which can not only ensure the reception of the first multicast service, but also save the configuration of the feedback resource, and is conducive to improving the resource utilization rate.​

[0143] In another possible manner, the network device may determine that all terminal devices in the first group of terminal devices that receive the first multicast service need to provide feedback on the first multicast service, and the network device may configure all terminal devices in the first group of terminal devices to provide feedback on the first multicast service.

[0144] Method 2

[0145] The network device may determine whether the terminal device needs to provide feedback on the multicast service based on the physical distance and / or transmission distance between the terminal device and the network device.

[0146] For example, if the physical distance between the terminal device and the network device exceeds a set threshold, the network device may indicate that the terminal device needs to provide feedback on the received multicast service; conversely, if the physical distance between the terminal device and the network device does not exceed the set threshold, the network device may indicate that the terminal device does not need to provide feedback on the received multicast service.

[0147] Method 3

[0148] The network device may determine whether the terminal device needs to provide feedback on the multicast service based on the channel quality status of the terminal device.

[0149] Exemplarily, the network device may determine the channel quality status of the terminal device based on the transmission channel (e.g., PDSCH) corresponding to the first multicast service. If the channel quality of the terminal device is poor, the network device may indicate that the terminal device needs to provide feedback on the received multicast service; conversely, if the channel quality of the terminal device is good, the network device may indicate that the terminal device does not need to provide feedback on the received multicast service.

[0150] Step 502: The terminal device receives first multicast configuration information.

[0151] An example is that the terminal device can receive the first multicast configuration information from the network device through a radio resource control (RRC) connection.

[0152] As another example, the terminal device may receive the first multicast configuration information from the network device through a common channel or a system message.

[0153] Another example is that the terminal device may receive first multicast configuration information from the network device during a random access process.

[0154] Step 503: The network device sends a first multicast service to the terminal device.

[0155] Step 504: The terminal device receives the first multicast service according to the first multicast configuration information.

[0156] One possible implementation method is that when the first multicast configuration information includes not only the first indication information but also the G-RNTI1 associated with the first multicast service, the terminal device can de-interlace the DCI1 from the network device according to the G-RNTI 1, and the DCI1 is used to schedule the multicast PDSCH1, and then the terminal device receives the first multicast service carried by the multicast PDSCH1.

[0157] Step 505: After receiving the first multicast service, the terminal device determines whether to provide feedback on the first multicast service according to the first indication information. If so, the subsequent steps are executed; otherwise, the subsequent steps are stopped.

[0158] In a possible embodiment, in step 505, the terminal device may determine whether to provide feedback on the first multicast service according to the first indication information in any one or more of the following ways.

[0159] Method 1

[0160] The terminal device determines whether to provide feedback on the received first multicast service based on the bit value of the bit position corresponding to the first multicast service in the first indication information, or determines whether to provide feedback on the received first multicast service based on the special field in the first indication information.

[0161] Specifically, when the terminal device receives the first indication information, and the value of the bit corresponding to the terminal device in the first indication information is the first set value (for example, "1"), the terminal device determines that it is necessary to provide feedback on the first multicast service. When the terminal device receives the first indication information, and the value of the bit corresponding to the terminal device in the first indication information is the second set value (for example, "0"), the terminal device determines that it is not necessary to provide feedback on the first multicast service.

[0162] Alternatively, after the terminal device receives the first indication information, if the first indication information includes a field agreed upon in the protocol, the terminal device determines that feedback on the first multicast service is required. After the terminal device receives the first indication information, if the first indication information does not include a field agreed upon in the protocol, the terminal device determines that feedback on the first multicast service is not required.

[0163] Method 2

[0164] If the terminal device determines that the first indication information indicates the transmission resources of the first multicast service, it will provide feedback on the received first multicast service; if the terminal device determines that the first indication information does not indicate the transmission resources of the first multicast service, it will not provide feedback on the received first multicast service.

[0165] Method 3

[0166] After the terminal device receives the first indication information, if the first indication information includes a threshold value of a signal quality parameter, and the terminal device determines that the value of the signal quality parameter of the first multicast service is less than or equal to the threshold value, the terminal device determines to provide feedback for the first multicast service.

[0167] Exemplarily, the terminal device may determine that feedback is needed for the first multicast service based on at least one of the following conditions. Condition one, when the RSRP value measured by the terminal device for the first multicast service is less than or equal to the RSRP threshold value; Condition two, when the RSRQ value measured by the terminal device for the first multicast service is less than or equal to the RSRQ threshold value; Condition three, when the SINR value measured by the terminal device for the first multicast service is less than or equal to the SINR threshold value. Condition four, when the CQI value measured by the terminal device for the first multicast service is less than or equal to the CQI threshold value. Condition five, when the RSSI value measured by the terminal device for the first multicast service is less than or equal to the RSSI threshold value.

[0168] Step 506: When the terminal device determines that feedback on the first multicast service is required, the terminal device sends first feedback information to the network device, where the first feedback information corresponds to the first multicast service.

[0169] Specifically, the first feedback information sent by the terminal device to the network device may be positive feedback information, such as a positive acknowledgement (ACK) or a negative acknowledgement (NACK). For example, if the terminal device correctly receives the first multicast service, the terminal device needs to send positive feedback information (ACK) to the network device. If the terminal device does not correctly receive the first multicast service, the terminal device needs to send negative feedback information (NACK) to the network device.

[0170] Exemplarily, from the perspective of a network device, the network device determines the mode (unicast or multicast) to use for retransmitting the first multicast service based on the received first feedback information corresponding to the first multicast service. In one example, based on the number of NACK feedback information received corresponding to the first multicast service, if the number is less than or equal to a certain threshold (the threshold is a positive integer greater than or equal to 1), the network device retransmits the first multicast service to each terminal that feedbacks the NACK information via unicast; otherwise, the network device retransmits the first multicast service via multicast; in another example, as long as the network receives NACK feedback information corresponding to the first multicast service, it retransmits the first multicast service via multicast.

[0171] The following describes possible implementations of the terminal device sending the first feedback information to the network device.

[0172] In a possible embodiment, the first indication information indicates a transmission resource of the first feedback information of the first multicast service, and the terminal device may use the transmission resource to send the first feedback information to the network device.

[0173] In another possible embodiment, the first indication information does not indicate the transmission resources of the first feedback information of the first multicast service, the terminal device receives resource indication information from the network device, the resource indication information indicates the transmission resources configured by the network device for the terminal device, and the terminal device transmits the first feedback information on the transmission resources configured by the network device.

[0174] In other possible embodiments, the first indication information does not indicate the transmission resource of the first feedback information of the first multicast service, and the terminal device may send the first feedback information to the network device on the transmission resource agreed upon in the protocol.

[0175] In the above embodiment, for the terminal device, the network device can configure the PUCCH resources corresponding to the first feedback information, and the terminal device can send the first feedback information on the PUCCH resources. Since the terminal device may also receive unicast services from the network device, the terminal device also needs to provide feedback on the unicast services. In this way, there may be a conflict between the PUCCH resources used for HARQ feedback of the unicast services and the PUCCH resources used for the first feedback information. To this end, in order to address this problem, when the feedback resources of the first multicast service conflict with the feedback resources of the unicast service, the terminal device can determine whether to send the first feedback information of the first multicast service to the network device based on the priority of the feedback information. Specifically, the terminal device can use any one of the following two methods to determine how to provide feedback on the first multicast service and the unicast service.

[0176] Method 1: Priority is predefined by the protocol

[0177] Specifically, if the protocol pre-agreed that the priority of feedback information of multicast services is higher than the priority of feedback information of unicast services, the terminal device may give priority to sending the first feedback information corresponding to the first multicast service to the network device, and discard the feedback information corresponding to the unicast service; if the protocol pre-agreed that the priority of feedback information of multicast services is not higher than the priority of feedback information of unicast services, the terminal device may give priority to sending the feedback information corresponding to the unicast service to the network device, and discard the first feedback information corresponding to the first multicast service.

[0178] Method 2: The priority is indicated by the network device through the third indication information

[0179] Specifically, the terminal device may receive third indication information from the network device, and the indication information is used to indicate the priority of the feedback information of the multicast service. The third indication information may be carried in a DCI or RRC message together with the multicast configuration information. In response to the third indication information, if the third indication information indicates that the priority of the feedback information of the first multicast service is the first priority (e.g., a high-level priority), the terminal device gives priority to sending the first feedback information corresponding to the first multicast service to the network device, and discards the feedback information corresponding to the unicast service; if the third indication information indicates that the priority of the feedback information of the first multicast service is the second priority (e.g., a low-level priority), the terminal device gives priority to sending the feedback information corresponding to the unicast service to the network device, and discards the first feedback information corresponding to the first multicast service.

[0180] Optionally, the third indication information may be 1 bit or multiple bits, which is not limited here. For example, when the third indication information is indicated by 1 bit, a bit position of "0" indicates the first priority, and a bit position of "1" indicates the second priority.

[0181] Optionally, the terminal device receives an information frame of downlink control information in format 1_0 sent by the network device through a physical downlink control channel or in format 1_1 sent by a physical downlink control channel, and the information frame includes the third indication information.

[0182] Optionally, after executing step 506, this embodiment 1 may further include step 507a: the terminal device determines to stop sending feedback information for the first multicast service. Implementations of the terminal device determining to stop sending feedback information for the first multicast service include implementation 1a and implementation 2a.

[0183] Implementation 1a

[0184] The terminal device determines to stop sending feedback information for the first multicast service according to the fourth indication information sent by the network device. Correspondingly, the above step 507a may specifically include step 507 and step 508.

[0185] Step 507: The network device sends fourth indication information to the terminal device, where the fourth indication information is used to instruct the terminal device to stop sending feedback information for the first multicast service.

[0186] Exemplarily, the fourth indication information may be carried in a DCI, an RRC message or a media access control (MAC) control element (CE).

[0187] Optionally, the method further includes step 508, where the terminal device sends stop feedback confirmation information to the network device, where the stop feedback confirmation information is used to instruct the terminal device to stop sending feedback information for the first multicast service.

[0188] Implementation 2a

[0189] The above step 507a may specifically include: the terminal device determines to stop feeding back the first multicast service according to a predefined parameter, wherein the predefined parameter may be the duration of the first timer or the first counting threshold.

[0190] In one example, the predefined parameter is the duration of a first timer. If the terminal device triggers the start of the first timer by sending feedback information, when the first timer times out, the terminal device determines to stop providing feedback for the first multicast service; when the terminal device subsequently sends the first feedback information on the feedback resource corresponding to the first multicast service, it triggers the restart of the first timer; when the first timer times out, the terminal device determines to stop providing feedback for the first multicast service.

[0191] In another example, the predefined parameter is a first counting threshold, the first counting threshold corresponds to a first counter, and the initial value of the first counter is 0. If the content transmitted by the terminal device on the feedback resource corresponding to the first multicast service does not include the first feedback information, the first counter value is incremented by 1. When the first counter value is greater than or equal to the first technical threshold, the terminal device determines to stop providing feedback for the first multicast service. In addition, if the content transmitted by the terminal device on the feedback resource corresponding to the first multicast service includes the first feedback information, the counter is cleared.

[0192] In addition, through the above-mentioned implementation method 1a and implementation method 2a, once the terminal device determines to stop sending feedback information for the first multicast service, the terminal device will perform at least one of the following actions: Action 1, stop sending feedback information for the first multicast service; Action 2, release the PUCCH resources configured for multicast feedback, thereby improving resource utilization. Action 3, indicate to the upper layer that the feedback corresponding to the first multicast service has stopped. The network device configures the feedback function and feedback resources for the terminal device, but if the terminal device does not use the feedback resources for a long time, it will cause a waste of communication resources. The communication prevention provided by this embodiment can timely release the feedback resources with low utilization rate, thereby improving the resource utilization of the communication system.

[0193] In a possible embodiment, in step 508, the stop feedback confirmation information may be carried in a MAC CE. Each MAC CE has a corresponding MAC subheader. The MAC subheader includes a logical channel identifier (LCID). The LCID is used to identify the corresponding MAC CE type. Figure 6A There are two possible implementations for the MAC CE format:

[0194] Method I:

[0195] The MAC CE length corresponding to the stop feedback determination information is 0, and the MAC CE is indicated by the logical channel identifier LCID. Exemplarily, the LCID is a first preset value, indicating that the terminal device stops sending feedback information for the first multicast service.

[0196] Another possible approach is that the stopping of feedback confirmation information may be indicated by the length of the MAC CE. For example, the length of the MAC CE is a first preset length, and the MAC CE with the first preset length is used to indicate 1 to stop sending feedback information for the first multicast service.

[0197] Method II:

[0198] The stop feedback confirmation information may be indicated by the fifth indication information in the MAC CE. The fifth indication information may be the G-RNTI1 associated with the first multicast service, or the service identifier of the first multicast service. For example, see Figure 6B When the MAC CE carries G-RNTI1, it means that the terminal device stops providing feedback on the first multicast service corresponding to the G-RNTI1.

[0199] According to the above content, on the one hand, the terminal device can realize feedback on the multicast service, and on the other hand, the terminal device can provide feedback on the first multicast service according to the first indication information. Then, the network device can instruct the terminal device to provide feedback on the multicast service with higher latency requirements through the first indication information, thereby effectively improving the reliability of the multicast service with higher latency requirements and enhancing the flexibility of the configuration.

[0200] Example 2

[0201] like Figure 7 As shown, the communication method provided in the embodiment of the present application can also be applied to the feedback mechanism of multiple multicast services at the same time, and the network device can configure different feedback functions and / or feedback resources for different multicast services. Figure 4A Taking the terminal device 1 in FIG. 1 as an example, the method may include the following steps.

[0202] In step 701 , a network device sends first multicast configuration information to terminal device 1 . The first multicast configuration information corresponds to a first multicast service. The first multicast configuration information includes first indication information. The first indication information is used to indicate sending first feedback information for the first multicast service.

[0203] The first multicast configuration information is used to instruct the terminal device to receive the first multicast service. The first multicast configuration information can be carried in an RRC message, a system message, or a common channel. The first multicast configuration information is multicast configuration information corresponding to the first multicast service. The specific content of the multicast configuration information and the specific content that the first multicast configuration information may further include can be found in step 501 and will not be repeated here.

[0204] Step 701a: The network device sends second multicast configuration information to terminal device 1. The second multicast configuration information corresponds to a second multicast service. The second multicast configuration information includes second indication information. The second indication information is used to indicate that feedback information does not need to be sent for the second multicast service.

[0205] The second multicast configuration information is used to instruct the terminal device to receive the second multicast service. The first multicast configuration information can be carried in the RRC message. The content included in the first multicast configuration information can be specifically referred to step 501 and will not be repeated here.

[0206] For example, the second multicast service and the first multicast service in step 701 and step 701a are different multicast services. The following describes these two methods respectively.

[0207] Method A: The first multicast configuration information and the second multicast configuration information can be carried in different messages. For example, the first multicast configuration information is carried in the first RRC message, and the second multicast configuration information can be carried in the second RRC message. The network device sends the first RRC message and the second RRC message to the terminal device respectively. The first multicast configuration information in the first RRC message indicates that terminal device 1 receives the first multicast service, and the second multicast configuration information in the second RRC message indicates that terminal device 2 receives the second multicast service.

[0208] Method B: The first multicast configuration information and the second multicast configuration information are carried in the same message. For example, the network device sends a third RRC message to the terminal device, and the third RRC message includes the first multicast configuration information and the second multicast configuration information, wherein the first multicast configuration information corresponds to the first multicast service, and the second multicast configuration information corresponds to the second multicast service, the first multicast configuration information includes the first indication information, and the second multicast configuration information includes the second indication information.

[0209] In one possible embodiment, in steps 701 and 701a, the network device may use an explicit or implicit indication method in the first indication information and / or the second indication information to indicate to the terminal device whether to send feedback information. Specifically, please refer to the three methods of the first indication information in step 501 above, which will not be repeated here.

[0210] It should be noted that the first indication information and the second indication information sent by the network device can use the same method among the three methods in the above step 501 to indicate whether the terminal device 1 feeds back, or can use different methods to indicate whether the terminal device 1 feeds back. This embodiment of the present application does not limit this.

[0211] Step 702: Terminal device 1 receives first multicast configuration information.

[0212] Step 702a: Terminal device 1 receives second multicast configuration information.

[0213] In the above steps 702 and 702a, the terminal device 1 receives the first multicast configuration information and the second multicast configuration information sent by the network device, including:

[0214] As an example, the terminal device 1 may receive the first multicast configuration information and the second multicast configuration information from the network device via a radio resource control (RRC) connection message.

[0215] As another example, the terminal device 1 may receive the first multicast configuration information and the second multicast configuration information from the network device through a common channel or a system message.

[0216] Another example is that the terminal device 1 can receive first multicast configuration information and second multicast configuration information from the network device during the random access process.

[0217] Step 703 : The network device sends the first multicast service and the second multicast service to terminal device 1 .

[0218] It should be noted that the first multicast service and the second multicast service may be sent in the same message or separately.

[0219] Step 704: Terminal device 1 receives the first multicast service according to the first multicast configuration information.

[0220] One possible implementation method is that when the first multicast configuration information includes not only the first indication information but also the G-RNTI1 associated with the first multicast service, the terminal device 1 can de-interlace the DCI1 from the network device according to the G-RNTI 1 in the first RRC message. The DCI1 is used to schedule the multicast PDSCH1, and the terminal device then receives the first multicast service carried by the multicast PDSCH1.

[0221] Step 704a: Terminal device 1 receives the second multicast service according to the second multicast configuration information.

[0222] With respect to the above-mentioned step 704 and step 704a, the terminal device may receive the first multicast configuration information and / or the second multicast configuration information in any one of the following ways.

[0223] For method A in the above steps 701 and 701a, on the one hand, the terminal device 1 can descramble the DCI1 from the network device according to the G-RNTI 1 in the first RRC message, and the DCI1 is used to schedule multicast PDSCH1, so that the terminal device receives the first multicast service carried by multicast PDSCH1; on the other hand, the terminal device 1 can descramble the DCI2 from the network device according to the G-RNTI 2 in the second RRC message, and the DCI2 is used to schedule multicast PDSCH2, so that the terminal device receives the second multicast service carried by multicast PDSCH2.

[0224] For method B in the above steps 701 and 701a, the terminal device 1 can de-scramble the DCI from the network device according to the G-RNTI in the third RRC message. The DCI is used to schedule multicast PDSCH1 and multicast PDSCH2, and then the terminal device receives the first multicast service carried by multicast PDSCH1 and the second multicast service carried by multicast PDSCH2.

[0225] In step 705, the terminal device 1 may determine whether to provide feedback on the first multicast service based on the first indication information, and determine whether to provide feedback on the second multicast service based on the second indication information. If so, execute the subsequent step 706; otherwise, stop executing the subsequent steps.

[0226] Specifically, the terminal device 1 may determine whether to provide feedback for the first multicast service according to the first indication information and determine whether to provide feedback for the second multicast service according to the second indication information in any one or more of the ways listed in step 505 above, which will not be repeated here.

[0227] Step 706: Terminal device 1 sends first feedback information to the network device, where the first feedback information corresponds to the first multicast service.

[0228] The terminal device 1 sends first feedback information to the network device. The first feedback information can be ACK or NACK. For example, if the terminal device 1 correctly receives the first multicast service, the terminal device 1 needs to send positive feedback information (ACK) to the network device. If the terminal device 1 does not correctly receive the first multicast service, the terminal device 1 needs to send negative feedback information (NACK) to the network device.

[0229] Exemplarily, from the perspective of the network device, the network device determines the manner (unicast or multicast) used for retransmitting the first multicast service according to the received first feedback information corresponding to the first multicast service. In an example, the network device determines the manner (unicast or multicast) used for retransmitting the first multicast service according to the number of NACK feedback information corresponding to the first multicast service. If the number is less than or equal to a threshold (the threshold is a positive integer greater than or equal to 1), the network device retransmits the first multicast service to each terminal device feeding back NACK information through unicast; otherwise, the network device retransmits the first multicast service through multicast. In another example, as long as the network device receives NACK feedback information corresponding to the first multicast service, the network device retransmits the first multicast service through multicast.

[0230] The possible implementation manners of the terminal device sending the first feedback information to the network device are described above after step 506, and thus are not repeated here.

[0231] In a possible embodiment, for the same multicast service, the network device can instruct at least one terminal device in the same group of terminal devices to feed back the multicast service, and at least one terminal device in the same group of terminal devices not to feed back the multicast service. Based on this, the network device can determine the manner (unicast or multicast) used for retransmitting the first multicast service according to the received first feedback information corresponding to the first multicast service. Figure 7 The communication method shown in the figure can further include the following steps 701b, 703a and 704b. In this embodiment, the terminal device 2 does not feed back the first multicast service after receiving the first multicast service.

[0232] Step 701b: The network device sends third multicast configuration information to the terminal device 2, the third multicast configuration information corresponding to the multicast service, the third multicast configuration information including indication information for indicating that the terminal device 2 does not need to feed back the first multicast service.

[0233] The first group of terminal devices includes the terminal device 1 and the terminal device 2, as shown in the figure. Figure 4A

[0234] Step 703a: The network device sends the first multicast service to the terminal device 2.

[0235] In a possible implementation, the network device can send the first multicast service to the terminal device 1 and the terminal device 2 in the first group of terminal devices through multicast.

[0236] Step 704b: The terminal device 2 receives the first multicast service.

[0237] In a possible embodiment, before step 701 is performed, the network device needs to determine the terminal device that needs to feed back the multicast service. The determination method of the network device can include one or more of the following methods. ​

[0238] Method 1: The network device can determine whether the multicast service sent by the network device to the terminal device is a multicast service of interest to the terminal device based on the service requirements of the terminal device group to which the terminal device belongs. If so, it determines that the terminal device needs to provide feedback on the multicast service.

[0239] For example, in the above embodiment, the terminal device 1 is in the group of terminal devices Figure 4A For the first group of terminal devices in the network, assume that the first terminal device has a high reliability requirement for the first multicast service. One possible approach is for the network device to determine that the terminal devices in the first group of terminal devices that receive the first multicast service need to provide feedback on the first multicast service. That is, the network device can configure terminal device 1 in the first group of terminal devices to provide feedback on the first multicast service, while terminal device 2 does not provide feedback on the first multicast service. Another possible approach is for the network device to determine that all terminal devices in the first group of terminal devices need to provide feedback on the first multicast service.

[0240] For another example, assuming that the service requirement of the first terminal device for the second multicast service is low reliability, one possible approach is that the network device may configure the terminal device 1 of the first group of terminal devices not to provide feedback for the second multicast service.

[0241] In a second approach, the network device may determine whether the terminal device needs to provide feedback on the multicast service based on the relative physical distance between the terminal device and the network device.

[0242] For example, if the physical distance between terminal device 1 and the network device exceeds a set threshold, the network device may indicate that terminal device 1 needs to provide feedback on the received first multicast service; conversely, if the physical distance between terminal device 2 and the network device does not exceed the set threshold, the network device may indicate that terminal device 2 does not need to provide feedback on the received first multicast service.

[0243] In a third approach, the network device may determine whether the terminal device needs to provide feedback on the multicast service based on the channel quality status of the terminal device.

[0244] For example, the network device may determine the channel quality status of the terminal device based on the transmission channel (e.g., PDSCH) of the first multicast service. If the channel quality of terminal device 1 is poor, the network device may instruct terminal device 1 to provide feedback on the received first multicast service; conversely, if the channel quality of terminal device 2 is good, the network device may instruct terminal device 2 not to provide feedback on the received first multicast service.

[0245] For another example, the network device may determine the channel quality status of the terminal device based on the transmission channels (e.g., PDSCH) of the first and second multicast services. If the transmission channel quality of the first multicast service corresponding to terminal device 1 is poor, the network device may instruct terminal device 1 to provide feedback on the received first multicast service; if the transmission channel quality of the second multicast service corresponding to terminal device 1 is good, the network device may instruct terminal device 1 not to provide feedback on the received second multicast service.

[0246] In a possible embodiment, in the above step 706, when the feedback resource of the first multicast service conflicts with the feedback resource of the unicast service, the terminal device 1 can determine whether to send the first feedback information of the first multicast service to the network device according to the priority of the feedback information. Figure 5 The description of the method shown will not be repeated here.

[0247] In a possible embodiment, after executing step 706, the embodiment 1 may further include step 707a: the terminal device determines to stop sending feedback information for the first multicast service. The implementation modes of the terminal device 1 determining to stop sending feedback information for the first multicast service are implementation mode 1b and implementation mode 2b.

[0248] Implementation 1b

[0249] The terminal device 1 determines to stop sending feedback information for the first service according to the fourth indication information sent by the network device. Correspondingly, the above step 707a may specifically include step 707 and step 708.

[0250] Step 707: The network device sends fourth indication information to the terminal device 1. The fourth indication information is used to instruct the terminal device 1 to stop sending feedback information for the first multicast service.

[0251] Exemplarily, the fourth indication information may be carried in DCI, RRC message or MAC CE.

[0252] Optionally, the method further includes step 708, where the terminal device 1 sends a stop feedback confirmation message to the network device, instructing the terminal device 1 to stop sending feedback information for the first multicast service. In this way, the terminal device 1 releases the PUCCH resources configured for multicast feedback, thereby improving resource utilization.

[0253] Implementation 2b

[0254] The above step 507a may be specifically as follows: the terminal device 1 determines to stop feeding back the first multicast service according to a predefined parameter. The predefined parameter may be a first timer or a first counting threshold. For details, please refer to the above implementation 2a, which will not be repeated here.

[0255] In addition, after the above implementations 1b and 2b, once the terminal device determines to stop sending feedback information for the first multicast service, the terminal device will perform at least one of the following actions: Action 1: Stop sending feedback information for the first multicast service; Action 2: Release the PUCCH resources configured for multicast feedback, thereby improving resource utilization. Action 3: Instruct the upper layer that feedback for the first multicast service has stopped. As can be seen, if the terminal device is configured with feedback functions and feedback resources, but if the terminal device does not use the feedback resources for a long time, this method can avoid resource waste and facilitate the timely release of the feedback resources.

[0256] In a possible embodiment, the stop feedback confirmation information in step 708 can be carried in a MAC CE. Each MAC CE has a corresponding MAC subheader. The MAC subheader includes a logical channel identifier (LCID). The LCID is used to identify the corresponding MAC CE type. Figure 6A For two possible implementations of the MAC CE format, please refer to Method I and Method II listed after step 508 in the first embodiment.

[0257] In an embodiment of the present application, the network device can configure different feedback functions and / or feedback resources for different multicast services. On the one hand, the terminal device can provide feedback on the multicast service. On the other hand, because the first indication information indicates feedback on the first multicast service, the terminal device can provide feedback on the multicast service with higher latency requirements indicated by the network device, thereby effectively improving the reliability of the multicast service with higher latency requirements.

[0258] Example 3

[0259] like Figure 8 As shown, the network device can dynamically control the terminal device to turn on or off the feedback function through the indication information. The method may include the following steps.

[0260] Step 801: A network device sends first multicast configuration information to a terminal device, where the first multicast configuration information corresponds to a first multicast service.

[0261] In one possible implementation, the first multicast configuration information may include configuration information of feedback information corresponding to the first multicast service, for example, the configuration information includes the feedback timing duration of the first feedback information of the first multicast service, the codebook used by the first feedback information, or the transmission resources used to send the first feedback information.

[0262] The first multicast configuration information is used to instruct the terminal device to receive the first multicast service. The first multicast configuration information can be carried in an RRC message, a system message, or a common channel. The first multicast configuration information is multicast configuration information corresponding to the first multicast service. The specific content of the multicast configuration information and the specific content included in the first multicast configuration information can be found in step 501 and will not be repeated here.

[0263] Step 802: The terminal device receives first multicast configuration information.

[0264] An example is that the terminal device can receive the first multicast configuration information from the network device through a radio resource control (RRC) connection.

[0265] As another example, the terminal device may receive the first multicast configuration information from the network device through a common channel or a system message.

[0266] Another example is that the terminal device may receive first multicast configuration information from the network device during a random access process.

[0267] Step 803: The network device sends a first multicast service to the terminal device.

[0268] Step 804: The terminal device receives the first multicast service according to the first multicast configuration information.

[0269] One possible implementation method is that when the first multicast configuration information includes not only the first indication information but also the G-RNTI1 associated with the first multicast service, the terminal device can de-interlace the DCI1 from the network device according to the G-RNTI 1 in the first RRC message. The DCI1 is used to schedule the multicast PDSCH1, and the terminal device then receives the first multicast service carried by the multicast PDSCH1.

[0270] Since the terminal device does not provide feedback on the received multicast service by default, after executing step 804 , the terminal device will not provide feedback on the first multicast service currently received.

[0271] Step 805: The network device sends sixth indication information to the terminal device, where the sixth indication information is used to instruct the terminal device to start sending feedback information for the first multicast service.

[0272] Exemplarily, the sixth indication information may be carried in DCI, RRC message or MAC CE.

[0273] Step 806: The terminal device sends feedback start confirmation information to the network device. The feedback start confirmation information is used to instruct the terminal device to start sending feedback information for the first multicast service.

[0274] The start feedback confirmation information can be carried in the MAC CE. Each MAC CE has a corresponding MAC subheader, which includes an LCID. The LCID is used to identify the corresponding MAC CE type. Figure 6A There are two possible implementations for the MAC CE format:

[0275] Method A:

[0276] The start of feedback confirmation information may be indicated by LCID. Exemplarily, if LCID is a second preset value (eg, the number of bytes is 1), it indicates that the terminal device starts sending feedback information for the first multicast service.

[0277] Method B:

[0278] The start of feedback confirmation information may be indicated by the length of the MAC CE. Exemplarily, the length of the MAC CE is a second preset length, and the MAC CE with the second preset length is used to instruct the terminal device to start sending feedback information for the first multicast service.

[0279] Method C:

[0280] The start of feedback confirmation information may be indicated by indication information in the MAC CE, wherein the indication information may be an identifier of the terminal device or an identifier of the first multicast service.

[0281] Step 807: The network device sends a first multicast service to the terminal device.

[0282] Step 808: The terminal device continues to receive the first multicast service.

[0283] Step 809: The terminal device sends first feedback information to the network device, where the first feedback information corresponds to the first multicast service.

[0284] The first feedback information sent by the terminal device to the network device may be affirmative feedback information (ACK) or negative feedback information (NACK). For details, please refer to step 506 and will not be repeated here.

[0285] Step 810: The network device sends fourth indication information to the terminal device, where the fourth indication information is used to instruct the terminal device to stop sending feedback information for the first multicast service.

[0286] Exemplarily, the fourth indication information may be carried in DCI, RRC message or MAC CE.

[0287] Step 811: The terminal device sends a stop feedback confirmation message to the network device. The stop feedback confirmation message is used to instruct the terminal device to stop sending feedback information for the first multicast service.

[0288] In this way, after executing step 811, the terminal device no longer provides feedback for the first multicast service, and thus releases the PUCCH resources configured for multicast feedback to improve resource utilization. For specific examples, please refer to the above implementation methods 1a and 2a, which will not be repeated here.

[0289] In an embodiment of the present application, the network device can instruct the terminal device to enable the feedback function for the first multicast service through the sixth indication information, and instruct the terminal device to stop providing feedback for the first multicast service through the fourth indication information, thereby achieving flexible control of the feedback function and configuring the feedback function of the multicast service according to the real-time needs of the service, thereby improving the service reliability of the communication system while ensuring resource utilization.

[0290] Example 4

[0291] For the scenario in which the first indication information of the first multicast configuration information in the first embodiment is the threshold value of the signal quality parameter, the network device can enable the terminal device to determine whether to send feedback information according to the transmission quality of the multicast service by sending the threshold value of the signal quality parameter. The embodiment of the present application further Figure 9 The method flow chart shown provides a detailed description of how the terminal device provides feedback on the first multicast service in this scenario.

[0292] Step 901: The network device sends first multicast configuration information to the terminal device. The first multicast configuration information corresponds to a first multicast service. The first multicast configuration information includes first indication information. The first indication information includes a threshold value of a signal quality parameter corresponding to the first multicast service. The first indication information is used to indicate sending first feedback information for the first multicast service.

[0293] It should be noted that the first multicast configuration information is used to instruct the terminal device to receive the first multicast service. The first multicast configuration information can be carried in an RRC message, a system message, or a common channel. The first multicast configuration information is multicast configuration information corresponding to the first multicast service.

[0294] It should be noted that the first multicast configuration information can not include the first indication information in the step 901, that is, the first indication information (i.e., the threshold value of the signal quality parameter) can be carried in other RRC messages or system messages or common channels.

[0295] Exemplarily, the signal quality parameter can be RSRP, SINR or RSRQ, etc. The threshold value of the signal quality parameter can be an RSRP threshold value, an SINR threshold value or an RSRQ threshold value, etc. The specific content of the multicast configuration information and the specific content of the first multicast configuration information can be referred to the step 501 in the method 500. Figure 5

[0296] The terminal device receives the first multicast configuration information in step 902.

[0297] The network device sends the first multicast service to the terminal device in step 903.

[0298] The terminal device receives the first multicast service according to the first multicast configuration information in step 904.

[0299] In a possible implementation, when the first multicast configuration information includes the first indication information and a G-RNTI1 associated with the first multicast service, the terminal device can descramble a DCI1 from the network device according to the G-RNTI1, the DCI1 being used to schedule a multicast PDSCH1, and then the terminal device receives the first multicast service carried by the multicast PDSCH1.

[0300] The terminal device compares the value of the signal quality parameter of the first multicast service with the threshold value to determine whether to feed back the first multicast service in step 905. If yes, the subsequent step 906 is executed; otherwise, the subsequent step is stopped.

[0301] Specifically, when the value of the signal quality parameter of the first multicast service is less than or equal to the threshold value, the terminal device determines that the first multicast service needs to be fed back; when the value of the signal quality parameter of the first multicast service is greater than the threshold value, the terminal device determines that the first multicast service does not need to be fed back.

[0302] ​Exemplarily, the terminal device may determine that feedback is needed for the first multicast service based on at least one or more of the following conditions. Condition one, when the terminal device determines that the RSRP value of the first multicast service is less than or equal to the RSRP threshold value; Condition two, when the terminal device determines that the RSRQ value of the first multicast service is less than or equal to the RSRQ threshold value; Condition three, when the terminal device determines that the SINR value of the first multicast service is less than or equal to the SINR threshold value. Condition four, when the terminal device determines that the CQI value of the first multicast service is less than or equal to the CQI threshold value. Condition five, when the terminal device determines that the RSSI value of the first multicast service is less than or equal to the RSSI threshold value.

[0303] Step 906: If the terminal device determines that feedback on the first multicast service is required, the terminal device sends first feedback information corresponding to the first multicast service to the network device.

[0304] It can be seen that in an embodiment of the present application, the terminal device can determine whether to provide feedback based on the value of the signal quality parameter of the first multicast service, and only provide feedback when the signal quality of the received first multicast service is not good or poor, which can effectively improve the reliability of the multicast service and at the same time improve the resource utilization of the communication system.

[0305] Example 5

[0306] like Figure 10 As shown, through the communication method provided in the embodiment of the present application, the network device can simultaneously indicate the feedback function and / or feedback resource of the unicast service and the multicast service, so as to Figure 4A Taking the terminal device in as an example, the method may include the following steps.

[0307] Step 1001: The terminal device sends feedback capability information to the network device. The feedback capability information is used to indicate the capability of sending unicast feedback information and multicast feedback information on the same feedback resource.

[0308] Specifically, the terminal device indicates in the feedback capability information that the terminal device does not support sending feedback on unicast services and multicast services simultaneously on the same feedback resource (for example, the same timing).

[0309] Step 1002: The network device determines, based on the feedback capability information of the terminal device, a first transmission resource for first feedback information corresponding to a first multicast service of the terminal device and a second transmission resource for feedback information corresponding to a unicast service of the terminal device.

[0310] In an embodiment of the present application, when the feedback capability information indicates that the terminal device does not support feedback of unicast services and multicast services on the same feedback resource, the first transmission resource and the second transmission resource configured by the network device do not conflict, for example, the first transmission resource and the second transmission resource are resources on different time sequences.

[0311] In step 1003, the network device sends first multicast configuration information to the terminal device. The first multicast configuration information corresponds to a first multicast service and includes first indication information for instructing the sending of first feedback information for the first multicast service. The first indication information may also indicate a first transmission resource and a second transmission resource.

[0312] The first multicast configuration information is used to instruct the terminal device to receive the first multicast service. The first multicast configuration information can be carried in an RRC message, a system message, or a common channel. The first multicast configuration information is multicast configuration information corresponding to the first multicast service. The specific content of the multicast configuration information and the specific content that the first multicast configuration information may further include can be found in step 501 and will not be repeated here.

[0313] Step 1004: The terminal device receives first multicast configuration information.

[0314] An example is that the terminal device can receive the first multicast configuration information from the network device through a radio resource control (RRC) connection.

[0315] As another example, the terminal device may receive the first multicast configuration information from the network device through a common channel or a system message.

[0316] Another example is that the terminal device may receive first multicast configuration information from the network device during a random access process.

[0317] Step 1005: The network device sends a multicast service to the terminal device.

[0318] Optionally, the method further includes step 1006, where the network device sends a unicast service to the terminal device.

[0319] Step 1007: The terminal device receives the first multicast service according to the first multicast configuration information.

[0320] Optionally, when step 1006 is executed, the method further includes step 1008, where the terminal device receives a unicast service.

[0321] Step 1009: After receiving the first multicast service, the terminal device determines whether to provide feedback on the first multicast service according to the first indication information. If so, the subsequent step 1010 is executed; otherwise, the step 1010 is not performed.

[0322] The terminal device can use the first instruction information to Figure 5 Any one or more of the methods listed in step 505 are used to determine whether to provide feedback for the first multicast service, which will not be repeated here.

[0323] Step 1010: The terminal device sends first feedback information of a first multicast service on a first transmission resource, and sends feedback information of a unicast service on a second transmission resource.

[0324] In an embodiment of the present application, the terminal device reports to the network device whether it supports the ability to send feedback information of unicast services and feedback information of multicast services on the same feedback resource, so that the network device can schedule the timing of feedback information of unicast services and multicast services based on this feedback capability, avoiding the problem of timing conflict between feedback of unicast services and feedback of multicast services of the same terminal device.

[0325] Example 6

[0326] Currently, an LTE FDD radio frame is divided into 10 subframes, each of which is 1ms long. Different subcarrier spacings correspond to different slot lengths in the frame structure, as well as the relationship between slots and subframes. See Table 1 for details.

[0327] Table 1 Subcarrier spacing and subframe, time slot, number of slots / subframe

[0328]

[0329] The frame structures corresponding to the three sequence numbers (sequence number 1, sequence number 2, and sequence number 3) in the above table are as follows:

[0330] (1) The frame structure corresponding to Δf is {2.5kHz / 7.5kHz / 15kHz} is as follows Figure 11A As shown, 1 frame is equal to 10 ms, 1 frame is equal to 10 subframes, and 1 subframe contains 2 time slots. For 2.5 kHz, each time slot is 0.5 ms long and contains 1 OFDM symbol including CP.

[0331] (2) The frame structure corresponding to Δf of 1.25kHz is as follows Figure 11B As shown, 1 frame is equal to 10 ms, 1 frame is equal to 10 subframes, one subframe is equal to 1 time slot, and 1 subframe is equal to 1 ms.

[0332] (3) The frame structure corresponding to Δf of 0.37kHz is as follows Figure 11C As shown, the time length of each time slot is 3ms, and each time slot contains an OFDM symbol with CP. f In the initial 40ms interval of mod 4 = 0, there are 13 time slots, numbered from 0 to 12. In this 40ms, time slot 0 starts at 30720T s Among them, n f is the wireless frame number, Ts It is the basic unit of time.

[0333] Currently, the existing MBSFN configuration process is as follows: Network devices use the information element (IE) Multimedia Broadcast Multicast Service Network Subframe Configuration (MBSFN-SubframeConfig) to configure the subframes reserved for downlink multimedia broadcast multicast service network (MBSFN). In the MBSFN-SubframeConfig configuration, the network device uses the radioframe allocation period (radioframeAllocationPeriod) and the radioframe allocation offset (radioframeAllocationOffset) to configure the radio frames in which the MBSFN subframes will be located. The subframe allocation (subframeAllocation) and subframe allocation (v1430) are used to specify the specific MBSFN subframes. The specific configuration is shown in Table 2.

[0334] Table 2

[0335]

[0336]

[0337] In Table 2, (1), radioFrameAllocationPeriod, radioFrameAllocationOffset

[0338] It is used to indicate the radio frame position where the MBSFN subframe appears. When the formula: SFN mod radioFrameAllocationPeriod = radioFrameAllocationOffset is satisfied, the corresponding radio frame contains the MBSFN subframe, where SFN (System Frame Number) is the system frame number, n1 corresponds to the value 1, and n2 corresponds to the value 2.

[0339] (2) subframeAllocation, which is used to indicate which subframes are allocated as MBSFN subframes in the radio frame that meets the constraints of radioFrameAllocationPeriod and radioFrameAllocationOffset in (1).

[0340] (3) fourFrames: A string of bits is used to indicate the location of the MBSFN subframes in four consecutive radio frames. When a bit is set to "1", it means that the corresponding subframe is allocated for MBSFN. For FDD, it may be allocated to subframes #1, #2, #3, #6, #7, and #8.

[0341] (4) ourFrames-v1430 uses a string of bits to indicate the location of MBSFN subframes in four consecutive radio frames. For FDD: subframes #4 and #9 can also be configured as MBSFN subframes.

[0342] The problem with the existing technology is that the current MBSFN multicast mode is configured in units of subframes (1ms) (i.e., signaling is used to indicate which subframes can be used for MBMS). Figure 11C The Δf shown is a frame structure corresponding to 0.37kHz. At this time, the minimum unit that the terminal device can recognize is 1slot=3ms, which makes the terminal device configured with Δf of 0.37kHz uncertain in determining which position in the time domain resources can be used for MBMS.

[0343] An embodiment of the present application provides a communication method, which includes: for a terminal device (Δf is = 1.25 / 2.5 / 7.5 / 15kHz), the terminal device determines which subframes in the time domain reserved by the network device correspond to the downlink MBSFN service according to the MBSFN-SubframeConfig sent by the network device; but if the terminal device is also configured with a subcarrier spacing of Δf = 0.37kHz, that is, the corresponding minimum time unit (such as, when slot = 3ms), the terminal device determines which time domain positions the base station is reserved for downlink MBSFN use, which is different from the existing determination method.

[0344] Specifically, a terminal device is configured with a specific subcarrier spacing value and determines whether the minimum time unit corresponding to the subcarrier spacing value is valid for MBSFN. The method for determining the valid minimum time unit includes: only when the MBSFN subframe and the minimum time unit corresponding to the specific subcarrier spacing value are completely matched in the time domain, or when the u subframes corresponding to the minimum time unit corresponding to the specific subcarrier spacing value are all used by the network device for downlink MBSFN, will the terminal device receive MBMS sent by the network device in such time slots. For example, when Δf = 0.37kHz, the number of subframes corresponding to the minimum time unit u is 3.

[0345] For example, only when the MBSFN subframe and the time slot corresponding to Δf = 0.37kHz are completely matched in the time domain (that is, the time domain is overlapping), is it considered that the network device can use the corresponding time slot to send MBSFN. For a terminal device with Δf = 0.37kHz, when all subframes corresponding to a time slot are configured by the network device for downlink MBSFN, the terminal device will receive MBMS sent by the network device in such a time slot.

[0346] For example, Figure 11D As shown, the network device has configured subframes #1, #2, #3, #6, #7, and #8 as reserved for MBSFN use. For a terminal device configured with Δf = 0.37kHz (i.e., the frame structure corresponding to the last row), the header (the black-filled portion) is used to send the main system message and cannot be changed. Therefore, for a UE with Δf = 0.37kHz, subframes #1, #2, and #3 corresponding to slot #0 are reserved by the network device for downlink MBSFN use. Therefore, slot #0 meets the conditions, and the terminal device will receive the MBMS sent by the base station in slot #0. For slot #1, since only subframe #6 is an MBSFN subframe, and subframes #4 and #5 are non-MBSFN subframes, the terminal device will not receive the MBMS sent by the network device in slot #1. Similarly, for slot#2, subframes #7 and 8 corresponding to slot#2 are MBSFN subframes, but subframe 9 is a non-MBSFN subframe. Therefore, for terminal devices with Δf=0.37kHz, slot#2 is not reserved by the network device for downlink MBSFN use.

[0347] In the embodiment of the present application, the terminal device determines the position for receiving MBMS according to the above method, so that the terminal device configured with Δf=0.37kHz can accurately determine the time domain resources corresponding to the downlink MBSFN.

[0348] It should be noted that Figure 11D The corresponding communication method may be based on any possible implementation of the above-mentioned embodiments 1 to 5.

[0349] Example 7

[0350] Based on the method for determining the effective time slot in the sixth embodiment, the embodiment of the present application provides another communication method based on the new feature introduced in the R14 version of the standard - dedicated MBMS carrier (also known as MBMS dedicated carrier).

[0351] In the embodiments of the present application, a dedicated frequency domain carrier is used to send MBMS, but in the time domain, it is necessary to indicate which positions cannot be used for MBMS transmission, such as Figure 12A As shown in FIG. 3, it is a schematic diagram of radio frame structure after introducing a dedicated MBMS carrier, and at least one non-MBSFN (non-MBSFN) subframe is sent every 40 ms, which is used to send PSS / SSS / CRS / PBCH / PDCCH and PDSCH for sending system messages.

[0352] If necessary, the number of additional non-MBSFN subframes after non-MBSFN subframe #0 can be indicated by a broadcast message (main system message block), and optionally, the number of additional non-MBSFN subframes after non-MBSFN subframe #0 can be 0 or 1 or 2 or 3, and the position of the additional non-MBSFN subframes can be further indicated in system message block 1 (SIB 1). The specific indication can be configured by the NonMBSFN-SubframeConfig-r14 field in SIB 1, as shown in Table 3.

[0353] Table 3

[0354]

[0355]

[0356] As described above, the radioFrameAllocationPeriod and radioFrameAllocationOffset in the field are two parameters used to calculate the position of the non-MBSFN subframe in the radio frame, and the radio frame SFN containing the non-MBSFN subframe satisfies the following formula:

[0357] SFN mod radioFrameAllocationPeriod = radioFrameAllocationOffset;

[0358] Wherein, the position of the non-MBSFN subframe in the radio frame satisfying the above formula is indicated by SubframeAllocation, and SubframeAllocation occupies 9 bits, and bit 1-bit 9 in the 9 bits correspond to subframe 1-subframe 9, when the bit value is "0", it indicates that the corresponding subframe is an MBSFN subframe; when the bit value is "1", it indicates that the corresponding subframe is a non-MBSFN subframe.

[0359] like Figure 12A As shown in the figure, the base station is configured with an MBSFN dedicated carrier, and only subframe #0 is configured as a non-MBSFN subframe. There are no additional non-MBSFN subframes after subframe #0. Therefore, for the UE configured with Δf = 0.37 kHz (i.e., the frame structure corresponding to the last row), the black part is the position used to send the main system message and cannot be changed. Therefore, for the UE with Δf = 0.37 kHz, subframes #1, #2, and #3 corresponding to slot #0 are reserved by the base station for downlink MBSFN. Therefore, slot #0 meets the conditions. Similarly, the subframes corresponding to slots #1 to #12 are also used by the base station for downlink MBMS. Therefore, slots #1 to #12 also meet the conditions.

[0360] like Figure 12B As shown in the figure, the base station is configured with an MBMS dedicated carrier, subframe #0 is configured as a non-MBSFN subframe, and there are additional non-MBSFN subframes after subframe #0 (for example, the radioFrameAllocationperiod value is configured as rf4, the radioFrameAllocationOffset value is configured as 2, and the subframeAllocation configuration bit string is 001010000). From the above configuration parameters and the above figure, it can be seen that the base station configures the non-MBSFN subframe in radio frame #N+1, and the corresponding subframe #13 and subframe #15 in radio frame #N+1 are configured as non-MBSFN subframes.

[0361] Therefore, for a UE configured with Δf = 0.37 kHz (i.e., the frame structure corresponding to the last row), slot #6 does not meet the slot validity conditions because subframes #13 and #15 corresponding to slot #6 are configured as non-MBSFN subframes. Therefore, slot #6 is not valid for MBMS. The method for determining the validity of other slots is the same as above and is not repeated here.

[0362] In addition, after introducing Δf=0.37kHz, the possible changes are as follows:

[0363] For each codeword q, the bit block (in Identifies the number of bits in the codeword q on the physical channel transmitted in a subframe / time slot / sub-time slot). Before modulation, it needs to be scrambled as follows to generate a scrambled bit block

[0364]

[0365] Among them, the scrambling sequence c (q) (i) Initialize the scrambling code generator at the beginning of each subframe or time slot, and initialize the value c init Determined by the specific transmission channel type:

[0366]

[0367] Among them, n RNTI Corresponds to the RNTI associated with PDSCH transmission.

[0368] In addition, as mentioned above, different subcarrier spacings correspond to different time slot sizes. For example, when Δf = 1.25 / 2.5 / 7.5 / 15kHz, the corresponding time slot size is 1ms; while for Δf = 0.37kHz, the corresponding time slot size is 3ms. Therefore, in the above formula, in order to avoid ambiguity in time slots, it is necessary to specify in the protocol the time slot granularity used when determining the slot number when the subcarrier spacing is different: (1) When 0.37kHz is taken, the time slot number is determined with a time slot granularity of 3ms; within the starting 40ms interval that meets the condition nfmod4 = 0, there are 13 time slots, numbered from 0 to 12, and the time slot 0 position in this 40ms starts at 30720Ts. Among them, nf is the radio frame number and Ts is the basic time unit.

[0369] (2) When the frequency is 1.25kHz, the time slot granularity is 1ms; (3) When the frequency is 2.5 / 7.5 / 15kHz, the time slot granularity is 0.5ms.

[0370] In addition, when the subcarrier spacing is 0.37kHz, there are two reference signal (RS) mapping patterns, one pattern corresponds to a period of 2 symbols, and the other pattern corresponds to a period of 4 symbols. The two reference signal mapping patterns are as follows: Figure 12C and Figure 12D shown.

[0371] In addition, when the subcarrier spacing is 0.37kHz, it can be understood that the symbol is equivalent to the time slot. Therefore, if the time slot number is repeated periodically according to 0-12 (a total of 13 slots) in the case of 0.37kHz, since 13 is neither a multiple of 2 nor a multiple of 4, it will cause the reference signal pattern mapping graph to be misaligned. The corresponding problem description is as follows Figure 12E and Figure 12F As shown, in Figure 12E and Figure 12FAs indicated, the RS patterns corresponding to the two adjacent time slots Slot#12 and Slot#13 are the same, and there is a misalignment problem.

[0372] Based on the above problems, an embodiment of the present application provides a communication method, in which a virtual frame is introduced, and the virtual frame is numbered in groups of 52 time slots, that is, the time slots are numbered 0-51. The virtual frame structure corresponding to the 0.37kHz subcarrier spacing is shown in the figure below. The length of one virtual frame is 16*10ms=160ms, and one virtual frame consists of four frames with a length of 40ms. Each 40ms frame includes two parts: the first 1ms of every 40ms is used to send broadcast messages and other content, which is not included in the time slot number. The 39 ms from the 2nd ms to the 40th ms are numbered according to one time slot every 3ms; one virtual frame includes 52 time slots, so the time slots are numbered from slot#0 to slot#51. When entering the next virtual frame, the time slot number starts again from slot#0.

[0373] like Figure 12G As shown: for the 40ms frame labeled #0 (black part), the first 1ms is used to send broadcast and other content (black part), and the remaining 39ms are numbered according to every 3 ms as a time slot, corresponding to slot#0 to slot#12; in the 40ms frame labeled #1, the first 1ms is not used for time slot numbering, and time slot numbering starts from the second ms, and continues with slot#12, that is, starting from slot#13, and so on. For the 40ms frame labeled #3, the corresponding slot numbers are from slot#39 to slot#51.

[0374] The mapping of resource units with a subcarrier spacing of 0.37kHz is described as follows: the reference signal sequence r in OFDM symbol l l (m′) is mapped to a complex modulation symbol according to the following relationship

[0375]

[0376] Where p = 4, n s This is the 3ms slot number.

[0377]

[0378] -For MBMSFN reference signal pattern type 1

[0379]

[0380] l=0

[0381]

[0382] -For MBMSFN reference signal pattern type 2

[0383]

[0384] In the above formula, n s Available s 'Replace, and n s 'There are the following expressions:

[0385] n s '=[f(n f / 4)*13+n s ]mod 52, or n s '=f(n f / 4)*13+n s .

[0386] Among them, f() is the floor function, which is used to "round down", or "round down", or "round towards zero", that is, to take the largest integer not greater than x. Unlike "rounding up", rounding down directly takes the value on the number axis that is closest to the required value, that is, the largest integer value not greater than the required value. f is the frame number value of the wireless frame, n s It is the number of the 3ms slot, and the numbering starts from 0 to 12 according to the 40ms. Specifically, when the condition n is met f In the initial 40ms interval of mod 4 = 0, there are 13 time slots, numbered from 0 to 12. In this 40ms, time slot 0 starts at 30720T s Among them, n f is the wireless frame number, T s It is the basic unit of time.

[0387] In an embodiment of the present application, the above method can be used to enable the terminal device to determine the time-frequency position of the network device sending the multicast service under different carrier spacing configurations, so as to ensure that the terminal device can accurately receive the multicast service.

[0388] Regarding the above-mentioned embodiments 1 to 7, it should be noted that:

[0389] (1) The above-mentioned Embodiment 1 and Embodiment 7 can be implemented separately in different scenarios, or can be implemented in combination in the same scenario. Alternatively, different solutions involved in different embodiments can also be implemented in combination (for example, some or all of the solutions involved in Embodiment 1 can be implemented in combination with Embodiment 6), without specific limitation.

[0390] (2) The various flow charts described in the embodiments of this application (such as Figure 5、 Figure 7 、 Figure 8 、 Figure 9 、 Figure 10 The step numbers in the above are only an example of the execution flow, and do not constitute a limitation on the execution order of the steps. The steps in the embodiments of the present application have no strict execution order.

[0391] The above describes the scheme provided by the embodiments of the present application mainly from the perspective of interaction between the network device and the terminal device. It can be understood that, in order to implement the above functions, the network device or the terminal device can include hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should easily realize that, in combination with the units and algorithm steps of the examples described in the embodiments disclosed herein, the embodiments of the present application can be realized in the form of hardware or a combination of hardware and computer software. Whether a certain function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0392] The embodiments of the present application can divide the functional units of the terminal device and the network device according to the above method examples. For example, each functional unit can be divided according to each function, or two or more functions can be integrated into one unit. The integrated unit can be realized in the form of hardware or software functional unit.

[0393] In the case of using an integrated unit, Figure 13 A possible example block diagram of the apparatus involved in the embodiments of the present application is shown. As shown in Figure 13 The apparatus 1300 can include a processing unit 1302 and a communication unit 1303. The processing unit 1302 is used to control and manage the actions of the apparatus 1300. The communication unit 1303 is used to support the communication of the apparatus 1300 with other devices. Optionally, the communication unit 1303, also known as a transceiver unit, can include a receiving unit and / or a sending unit, which are used to perform receiving and sending operations, respectively. The apparatus 1300 can also include a storage unit 1301, which is used to store the program code and / or data of the apparatus 1300.

[0394] The apparatus 1300 may be a terminal device in any of the above embodiments, or may be a chip provided in the terminal device. The processing unit 1302 may support the apparatus 1300 in executing the actions of the terminal device in each of the above method examples. Alternatively, the processing unit 1302 mainly executes the internal actions of the terminal device in the method examples, and the communication unit 1303 may support the communication between the apparatus 1300 and the network device. For example, the communication unit 1303 may be used to execute Figure 5 Step 502, step 504, step 506 and step 508; Figure 7 Steps 702, 702a, 704, 704a, and 708 in Figure 8 Steps 802, 804, 806, 808, 809, and 811 in FIG. 8; and Figure 9 Steps 902, 904, and 906; and Figure 10 The processing unit 1302 can be used to perform steps 1001, 1004, 1007, 1008 and 1010. Figure 5 Step 505 in . And Figure 7 Step 705 in; and Figure 9 Step 905 in , and Figure 10 Step 1009 in .

[0395] In one possible design, the first multicast configuration information also includes a group-radio network temporary identifier G-RNTI and / or a multicast service identifier associated with the first multicast service, and the G-RNTI and / or the multicast service identifier are associated with the first indication information.

[0396] In one possible design, the first indication information indicates feedback on the first multicast service through a bit or a field; and / or, the first indication information is used to indicate a transmission resource of the first feedback information.

[0397] In one possible design, the first indication information includes a threshold value of a signal quality parameter; when the value of the signal quality parameter corresponding to the first multicast service is less than or equal to the threshold value, the communication unit 1303 sends the first feedback information to the network device.

[0398] In one possible design, the communication unit 1303 is also used to receive second multicast configuration information from the network device, where the second multicast configuration information corresponds to a second multicast service; the second multicast configuration information includes second indication information, and the second indication information is used to indicate that feedback information does not need to be sent for the second multicast service.

[0399] In one possible design, the communication unit 1303 is further used to send first feedback information corresponding to the first multicast service and / or second feedback information corresponding to the unicast service to the network device based on the priority of the feedback information.

[0400] In one possible design, the priority of the feedback information is determined by third indication information, where the third indication information comes from the network device; or the priority of the feedback information is predefined.

[0401] In one possible design, the third indication information is carried in DCI, where the DCI is used to schedule the physical downlink shared channel PDSCH that carries the first multicast service, or the third indication information is carried in a radio resource control RRC message.

[0402] In one possible design, the communication unit 1303 is further used to send a stop feedback confirmation message to the network device, where the stop feedback confirmation message is used to indicate to stop sending feedback information for the first multicast service.

[0403] In one possible design, the communication unit 1303 is also used to send a stop feedback confirmation message to the network device based on predefined parameters or a fourth indication message from the network device; wherein the fourth indication message is used to trigger the terminal device to send the stop feedback confirmation message to the network device.

[0404] In one possible design, the stop feedback confirmation information is indicated by a logical channel identifier LCID, and the LCID is carried by a media access control MAC subheader; or, the stop feedback confirmation information is indicated by the fifth indication information in the MAC control unit CE; or, the stop feedback confirmation information is indicated by the length of the MAC CE.

[0405] In one possible design, the communication unit 1303 is also used to send feedback capability information to the network device, where the feedback capability information is used to indicate the ability to send unicast feedback information and multicast feedback information on the same feedback resource; the unicast feedback information is feedback information corresponding to unicast services, and the multicast feedback information is feedback information corresponding to multicast services.

[0406] The apparatus 1300 may be a network device in any of the above embodiments, or may be a chip provided in the network device. The processing unit 1302 may support the apparatus 1300 in executing the actions of the network device in each of the above method examples. Alternatively, the processing unit 1302 mainly executes the internal actions of the network device in the method examples, and the communication unit 1303 may support the communication between the apparatus 1300 and the terminal device. For example, the communication unit 1303 may be used to execute Figure 5Step 501, step 503, step 507, Figure 7 Step 701, step 701a, step 701b, step 703, step 707; Figure 8 Steps 801, 803, 805, 807, and 810 in FIG. Figure 9 Step 901, step 903; and Figure 10 The processing unit 1302 can be used to execute steps 1002, 1003, 1005, and 1006. Figure 10 Step 1002 in .

[0407] In one possible design, the first multicast configuration information also includes a group-radio network temporary identifier G-RNTI and / or a multicast service identifier associated with the first multicast service, and the G-RNTI and / or the multicast service identifier are associated with the first indication information.

[0408] In one possible design, the first indication information indicates feedback on the first multicast service through a bit or a field; and / or, the first indication information is used to indicate a transmission resource of the first feedback information.

[0409] In one possible design, the first indication information includes a threshold value of a signal quality parameter.

[0410] In one possible design, before the communication unit 1303 sends the first multicast configuration information to the terminal device, the processing unit 202 is used to determine the terminal device that needs to send feedback information for the first multicast service based on at least one of the service requirements of the first multicast service, the physical relative distance between the terminal device and the network device, and the channel quality of the terminal device.

[0411] In one possible design, the communication unit 1303 is also used to send second multicast configuration information to the terminal device, where the second multicast configuration information corresponds to a second multicast service, and the second multicast configuration information includes second indication information, which is used to indicate that the terminal device does not need to send feedback information for the second multicast service.

[0412] In one possible design, before the communication unit 1303 receives the first feedback information from the terminal device, the communication unit 1303 is also used to send third indication information to the terminal device, and the third indication information is used to indicate the priority of the feedback information of the first multicast service.

[0413] In one possible design, the third indication information is carried in the downlink control information DCI, and the DCI is used to schedule the physical downlink shared channel PDSCH carrying the first multicast service.

[0414] In one possible design, the communication unit 1303 is used to send a fourth indication message to the terminal device, wherein the fourth indication message is used to instruct the terminal device to stop sending feedback information for the first multicast service; and to receive a stop feedback confirmation message from the terminal device, wherein the stop feedback confirmation message is used to instruct the terminal device to stop sending feedback information for the first multicast service.

[0415] In one possible design, the stop feedback confirmation information is indicated by a logical channel identifier LCID, and the LCID is carried by a media access control MAC subheader; or, the stop feedback confirmation information is indicated by the fifth indication information in the MAC control unit CE; or, the stop feedback confirmation information is indicated by the length of the MAC CE.

[0416] In one possible design, the communication unit 1303 is also used to receive feedback capability information from the terminal device, where the feedback capability information is used to indicate the ability of the terminal device to send unicast feedback information and multicast feedback information on the same feedback resource; the unicast feedback information is feedback information corresponding to unicast services, and the multicast feedback information is feedback information corresponding to multicast services.

[0417] It should be understood that the division of units in the above device is merely a division of logical functions. In actual implementation, they can be fully or partially integrated into one physical entity, or they can be physically separated. Moreover, the units in the device can all be implemented in the form of software called through processing elements; or they can all be implemented in the form of hardware; or some units can be implemented in the form of software called through processing elements, and some units can be implemented in the form of hardware. For example, each unit can be a separately established processing element, or it can be integrated into a certain chip of the device. In addition, it can also be stored in the memory in the form of a program, called by a certain processing element of the device and perform the function of the unit. In addition, all or part of these units can be integrated together, or they can be implemented independently. The processing element described here can also be a processor, which can be an integrated circuit with signal processing capabilities. In the implementation process, each step of the above method or each unit above can be implemented by the integrated logic circuit of the hardware in the processor element or in the form of software called through the processing element.

[0418] In one example, the unit in any of the above devices may be one or more integrated circuits configured to implement the above method, such as one or more application-specific integrated circuits (ASICs), one or more digital singnal processors (DSPs), one or more field programmable gate arrays (FPGAs), or a combination of at least two of these integrated circuit forms. For another example, when the unit in the device can be implemented in the form of a processing element scheduler, the processing element can be a processor, such as a general-purpose central processing unit (CPU), or other processor that can call a program. For another example, these units can be integrated together and implemented in the form of a system-on-a-chip (SOC).

[0419] The above-mentioned receiving unit is an interface circuit of the device, which is used to receive signals from other devices. For example, when the device is implemented as a chip, the receiving unit is the interface circuit of the chip used to receive signals from other chips or devices. The above-mentioned sending unit is an interface circuit of the device, which is used to send signals to other devices. For example, when the device is implemented as a chip, the sending unit is the interface circuit of the chip used to send signals to other chips or devices.

[0420] Please refer to Figure 14 , which is a structural diagram of a terminal device provided in an embodiment of the present application. It can be the terminal device in the above embodiment, used to implement the operations of the terminal device in the above embodiment. Figure 14 As shown, the terminal device includes an antenna 1410, a radio frequency section 1420, and a signal processing section 1430. Antenna 1410 is connected to radio frequency section 1420. In the downlink direction, radio frequency section 1420 receives information sent by network devices via antenna 1410 and sends the information to signal processing section 1430 for processing. In the uplink direction, signal processing section 1430 processes the information from the terminal device and sends it to radio frequency section 1420. Radio frequency section 1420 then processes the information from the terminal device and sends it to the network device via antenna 1410.

[0421] The signal processing unit 1430 may include a modem subsystem for processing data at various communication protocol layers; a central processing unit for processing the terminal device's operating system and application layers; and other subsystems, such as a multimedia subsystem for controlling the terminal device's camera and screen display, and a peripheral subsystem for connecting to other devices. The modem subsystem may be a separate chip.

[0422] The modem subsystem may include one or more processing elements 1431, such as a main control CPU and other integrated circuits. Furthermore, the modem subsystem may include a storage element 1432 and an interface circuit 1433. Storage element 1432 is used to store data and programs. However, the program used to execute the method performed by the terminal device in the above method may not be stored in storage element 1432 but rather in a memory external to the modem subsystem, and loaded by the modem subsystem when in use. Interface circuit 1433 is used to communicate with other subsystems.

[0423] The modem subsystem can be implemented using a chip comprising at least one processing element and an interface circuit, wherein the processing element is configured to execute each step of any of the methods performed by the terminal device described above, and the interface circuit is configured to communicate with other devices. In one implementation, the unit for implementing each step of the method described above can be implemented as a processing element scheduler. For example, the terminal device may include a processing element and a storage element, with the processing element invoking a program stored in the storage element to execute the method performed by the terminal device in the above method embodiments. The storage element can be a storage element located on the same chip as the processing element, i.e., an on-chip storage element.

[0424] In another implementation, the program for executing the method executed by the terminal device in the above method can be stored in a memory element on a different chip from the processing element, i.e., an off-chip memory element. In this case, the processing element calls or loads the program from the off-chip memory element to the on-chip memory element to call and execute the method executed by the terminal device in the above method embodiment.

[0425] In another implementation, the unit of the terminal device that implements each step of the above method may be configured as one or more processing elements, which are provided in the modem subsystem. The processing elements here may be integrated circuits, such as one or more ASICs, one or more DSPs, one or more FPGAs, or a combination of these integrated circuits. These integrated circuits may be integrated together to form a chip.

[0426] The units of the terminal device for implementing each step in the above method can be integrated together to realize the above method in the form of a SOC. The SOC chip can be integrated with at least one processing element and a storage element, and the above method executed by the terminal device can be realized in the form of the processing element calling the stored program of the storage element. Alternatively, the chip can be integrated with at least one integrated circuit for realizing the above method executed by the terminal device. Alternatively, in combination with the above implementation manners, the functions of part of the units can be realized in the form of a processing element calling a program, and the functions of part of the units can be realized in the form of an integrated circuit.

[0427] It can be seen that the above apparatus for a terminal device can include at least one processing element and an interface circuit, where the at least one processing element is configured to execute any of the methods executed by the terminal device provided in the above method embodiments. The processing element can execute part or all of the steps of the terminal device in a first manner, i.e., by calling a program stored in a storage element, in a second manner, i.e., by the integrated logic circuit of the hardware in the processor element in combination with instructions, or in a combination of the first manner and the second manner.

[0428] The processing element herein can be implemented by a processor as described above, and the functions of the processing element can be the same as those of the processing unit described in Figure 13 . For example, the processing element can be a general-purpose processor such as a CPU, and can also be one or more integrated circuits configured to implement the above method, such as one or more ASICs, or one or more microprocessors DSPs, or one or more FPGAs, or the like, or a combination of at least two of these integrated circuit forms. The storage element can be implemented by a memory, and the functions of the storage element can be the same as those of the storage unit described in Figure 13 . The storage element can be one memory, or collectively refer to a plurality of memories.

[0429] Figure 14 The terminal device shown can implement the processes of the method embodiments shown in Figure 5 , Figure 7 or Figure 8 . Figure 14 The operations and / or functions of each module in the terminal device shown are respectively for implementing the corresponding processes in the above method embodiments. For details, refer to the description in the above method embodiments, and the detailed description is appropriately omitted here.

[0430] Please refer to Figure 15 , which is a structural schematic diagram of a network device provided by the embodiments of the present application. The network device is used to implement the operations in the above embodiments. As shown in Figure 15 As shown, the network device includes: an antenna 1501, a radio frequency device 1502, a baseband device 1503. The antenna 1501 is connected with the radio frequency device 1502. In the uplink direction, the radio frequency device 1502 receives the information sent by the terminal device through the antenna 1501, and sends the information sent by the terminal device to the baseband device 1503 for processing. In the downlink direction, the baseband device 1503 processes the information of the terminal device and sends it to the radio frequency device 1502. The radio frequency device 1502 processes the information of the terminal device and sends it to the terminal device through the antenna 1501.

[0431] The baseband device 1503 can include one or more processing elements 15031, for example, including a master CPU and other integrated circuits. In addition, the baseband device 1503 can also include a storage element 15032 and an interface 15033, the storage element 15032 is used to store programs and data; the interface 15033 is used to interact with the radio frequency device 1502. The interface is, for example, a common public radio interface (common public radio interface, CPRI). The above device for network equipment can be located in the baseband device 1503, for example, the above device for network equipment can be a chip on the baseband device 1503, which includes at least one processing element and interface circuit, wherein the processing element is used to execute each step of the method executed by the above network equipment, and the interface circuit is used to communicate with other devices. In one implementation, the unit for implementing each step of the above method can be implemented by scheduling the program of the processing element, for example, the device for network equipment includes a processing element and a storage element, and the processing element calls the program stored in the storage element to execute the method executed by the network equipment in the above method embodiment. The storage element can be a storage element on the same chip as the processing element, that is, an on-chip storage element, or a storage element on a different chip from the processing element, that is, an off-chip storage element.

[0432] In another implementation, the unit for implementing each step of the above method can be configured as one or more processing elements, which are arranged on the baseband device. The processing element here can be an integrated circuit, for example: one or more ASICs, or one or more DSPs, or one or more FPGAs, or a combination of these integrated circuits. These integrated circuits can be integrated together to form a chip.

[0433] The units implementing the various steps of the above method in the network device can be integrated together and implemented in the form of a system-on-a-chip (SOC). For example, the baseband device includes the SOC chip to implement the above method. The chip can integrate at least one processing element and a storage element, and the processing element can call the program stored in the storage element to implement the above method performed by the network device; alternatively, the chip can integrate at least one integrated circuit to implement the above method performed by the network device; or, a combination of the above implementation methods can be used, with the functions of some units implemented by the processing element calling the program, and the functions of some units implemented by the integrated circuit.

[0434] As can be seen, the above-mentioned apparatus for a network device may include at least one processing element and an interface circuit, wherein the at least one processing element is used to execute any of the methods performed by the network device provided in the above method embodiments. The processing element may execute some or all of the steps performed by the network device in a first manner: by calling a program stored in a storage element; or in a second manner: by executing some or all of the steps performed by the network device through the hardware integrated logic circuit in the processor element in combination with instructions. Of course, the first and second manners may also be combined to execute some or all of the steps performed by the above-mentioned network device.

[0435] The processing element here is the same as described above and can be implemented by a processor. The function of the processing element can be Figure 13 The processing unit described in the preceding claims has the same function. For example, the processing element may be a general-purpose processor, such as a CPU, or one or more integrated circuits configured to implement the above method, such as one or more ASICs, or one or more microprocessors DSPs, or one or more FPGAs, or a combination of at least two of these integrated circuit forms. The storage element may be implemented by a memory, and the function of the storage element may be the same as Figure 13 The storage element can be a single memory or a collective term for multiple memories.

[0436] Figure 15 The network equipment shown is capable of Figure 5 、 Figures 7 to 10 The illustrated method embodiment involves various processes of a network device. Figure 15 The operations and / or functions of the modules in the network device are respectively for implementing the corresponding processes in the above method embodiments. For details, please refer to the description in the above method embodiments. To avoid repetition, detailed description is appropriately omitted here.

[0437] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0438] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0439] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0440] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0441] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. A communication method, characterized in that: include: receiving multicast subframe configuration information from a network device, where the multicast subframe configuration information indicates a subframe for transmitting a multicast service; Determining a subcarrier spacing configured with a specific value, where the subcarrier spacing of the specific value is 0.37 kHz; Determine a minimum time unit corresponding to the subcarrier spacing of the specific value, where the minimum time unit is a time slot, and the length of the time slot is 3 ms; If all subframes in the minimum time unit are configured to be used for transmitting a multicast service, determining that the minimum time unit is a valid minimum time unit; A multicast service is received from the network device within the effective minimum time unit.

2. The method according to claim 1, characterized in that The multicast subframe configuration information is a multimedia broadcast multicast single frequency network subframe configuration MBSFN-SubframeConfig.

3. The method according to claim 1 or 2, characterized in that The multicast subframe configuration information includes radio frame allocation time information, radio frame allocation offset value information and subframe allocation information; The radio frame allocation time information and the radio frame allocation offset value information are used to indicate a radio frame for transmitting a multicast service, and the subframe allocation information is used to indicate a subframe in the radio frame for transmitting a multicast service.

4. The method according to claim 1, wherein When the condition n is met f In the initial 40ms interval with mod 4=0, the minimum time units are numbered in ascending order from 0 to 12, where n f is the radio frame number.

5. The method according to claim 4, characterized in that The minimum time unit numbered 0 starts from 1 ms within the 40 ms interval.

6. A communication method, characterized in that: include: Sending multicast subframe configuration information to a terminal device, where the multicast subframe configuration information indicates a subframe for transmitting a multicast service; Determining that the terminal device is configured with a subcarrier spacing of a specific value, where the subcarrier spacing of the specific value is 0.37 kHz; Determine a minimum time unit corresponding to the subcarrier spacing of the specific value, where the minimum time unit is a time slot, and the length of the time slot is 3 ms; If all subframes in the minimum time unit are configured to be used for transmitting a multicast service, determining that the minimum time unit is a valid minimum time unit; Sending a multicast service to the terminal device in the effective minimum time unit.

7. The method according to claim 6, characterized in that The multicast subframe configuration information is a multimedia broadcast multicast single frequency network subframe configuration MBSFN-SubframeConfig.

8. The method according to claim 6 or 7, characterized in that The multicast subframe configuration information includes radio frame allocation time information, radio frame allocation offset value information and subframe allocation information; The radio frame allocation time information and the radio frame allocation offset value information are used to indicate a radio frame for transmitting a multicast service, and the subframe allocation information is used to indicate a subframe in the radio frame for transmitting a multicast service.

9. The method according to claim 6, characterized in that When the condition n is met f In the initial 40ms interval with mod 4=0, the minimum time units are numbered in ascending order from 0 to 12, where n f is the radio frame number.

10. The method according to claim 9, characterized in that The minimum time unit numbered 0 starts from 1 ms within the 40 ms interval.

11. A communication device, characterized in that: include: a communication module, configured to receive multicast subframe configuration information from a network device, wherein the multicast subframe configuration information indicates a subframe for transmitting a multicast service; a processing module, configured to determine a subcarrier spacing configured with a specific value, where the subcarrier spacing of the specific value is 0.37 kHz; The processing module is further configured to determine a minimum time unit corresponding to the subcarrier spacing of the specific value, where the minimum time unit is a time slot, and the length of the time slot is 3 ms; If all subframes in the minimum time unit are configured to be used for transmitting a multicast service, determining that the minimum time unit is a valid minimum time unit; The communication module is further configured to receive a multicast service from the network device within the effective minimum time unit.

12. The device according to claim 11, characterized in that The multicast subframe configuration information is a multimedia broadcast multicast single frequency network subframe configuration MBSFN-SubframeConfig.

13. The device according to claim 11 or 12, characterized in that The multicast subframe configuration information includes radio frame allocation time information, radio frame allocation offset value information and subframe allocation information; The radio frame allocation time information and the radio frame allocation offset value information are used to indicate a radio frame for transmitting a multicast service, and the subframe allocation information is used to indicate a subframe in the radio frame for transmitting a multicast service.

14. A communication device, characterized in that: include: A communication module, configured to send multicast subframe configuration information to a terminal device, wherein the multicast subframe configuration information indicates a subframe for transmitting a multicast service; a processing module, configured to determine that the terminal device is configured with a subcarrier spacing of a specific value, where the subcarrier spacing of the specific value is 0.37 kHz; The processing module is further configured to determine a minimum time unit corresponding to the subcarrier spacing of the specific value, where the minimum time unit is a time slot, and the length of the time slot is 3 ms; If all subframes in the minimum time unit are configured to be used for transmitting a multicast service, determining that the minimum time unit is a valid minimum time unit; The communication module is further configured to send a multicast service to the terminal device in the effective minimum time unit.

15. The device according to claim 14, characterized in that The multicast subframe configuration information is a multimedia broadcast multicast single frequency network subframe configuration MBSFN-SubframeConfig.

16. The device according to claim 14 or 15, characterized in that The multicast subframe configuration information includes radio frame allocation time information, radio frame allocation offset value information and subframe allocation information; The radio frame allocation time information and the radio frame allocation offset value information are used to indicate a radio frame for transmitting a multicast service, and the subframe allocation information is used to indicate a subframe in the radio frame for transmitting a multicast service.

17. A computer-readable storage medium, characterized in that The device comprises a program, and when the program is executed by a processor, the method according to any one of claims 1 to 5 is executed.

18. A computer-readable storage medium, characterized in that The device comprises a program, and when the program is executed by a processor, the method according to any one of claims 6 to 10 is executed.

19. A communication device, characterized in that: The device comprises at least one processor connected to a memory, and the at least one processor is used to read and execute a program stored in the memory so that the communication device executes the method according to any one of claims 1 to 5, or executes the method according to any one of claims 6 to 10.

20. A communication device, characterized in that: The device comprises at least one processor and an interface circuit, wherein the at least one processor communicates with other devices through the interface circuit, so that the communication device executes the method according to any one of claims 1 to 5, or executes the method according to any one of claims 6 to 10.

21. A chip, characterized in that: The chip is coupled to the memory and is configured to read and execute program instructions stored in the memory to implement the method according to any one of claims 1 to 5, or to implement the method according to any one of claims 6 to 10.

22. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer instructions, and when the instructions are executed on a computer, the computer is caused to execute the method according to any one of claims 1 to 5, or the method according to any one of claims 6 to 10.

23. A computer program product, characterized in that When the computer program product is called by a computer, the computer executes the method according to any one of claims 1 to 5 or the method according to any one of claims 6 to 10.

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